Echinacea & Goldenseal Glycerite by NOW

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Common Cold. Preliminary clinical research shows that taking a specific homeopathic product (Eupatorium perfoliatum D2) derived from boneset has a similar effect to aspirin on symptoms of the common cold (36793). More evidence is needed to rate boneset for this use.

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POSSIBLY EFFECTIVE

• Common cold. Taking echinacea orally while still healthy may help prevent the common cold, but the benefit is probably modest. Echinacea does not seem to have a significant benefit for treating colds that have already developed. Details: Three meta-analyses show a 10% to 58% reduction in the risk of developing a cold when taking various forms of echinacea (17520,17522,95652). A large clinical study shows that adults who use a specific echinacea extract (Echinaforce, A. Vogel Bioforce AG) 0.9 mL three times daily (2400 mg echinacea daily) for 4 months, with an increase to 0.9 mL five times daily (4000 mg echinacea daily) at the first sign of a cold, have 59% fewer cold episodes and 26% fewer days with cold symptoms than those taking placebo (18225). Many smaller studies have shown a non-significant trend toward a prophylactic benefit, but they were likely underpowered to detect a statistically significant difference (3282,6386,17521,95652). Research in adults who are deliberately infected with cold viruses shows that taking echinacea products either does not reduce the incidence of colds, or has a limited effect which is not statistically significant. Products used include E. angustifolia root extract 300 mg three times daily for 7 days before and 5 days after experimental infection (13419), an alcoholic extract of E. purpurea above-ground parts (EchinaGuard, Madaus AG) 2.5 mL three times daily for 7 days before and 7 days after experimental infection (12354), or echinacea 300 mg three times daily for 14 days before and 5 days after experimental infection (8228). These studies are small and have methodological problems. Some small clinical studies have suggested that taking E. purpurea extracts as a tincture or tea to treat the common cold modestly reduces symptom severity and reduces cold duration by a couple of days (6384,10320,10802,12355,14419,20062,111530). Specific products used in these studies include Echinilin by Inovobiologic Inc., and Echinacin and EchinaGuard by Madaus AG (10320,10802,12355,20062). In contrast, higher quality clinical research shows that taking E. purpurea alone or with E. angustifolia does not reduce duration or severity of cold symptoms when compared with placebo (10800,11970,17519,20059). Echinacea has also been evaluated in children. Preliminary clinical research in healthy children 4-12 years old shows that taking a specific E. purpurea product (Echinaforce Junior, A. Vogel) 400 mg three times daily for 4 months reduces the occurrence of cold symptoms, respiratory complications (such as pneumonia and otitis media), and antibiotic prescriptions by 30%, 52%, and 62%, respectively, when compared with vitamin C 50 mg three times daily. Taking echinacea also reduces the average duration of symptoms during respiratory illness by an average of 1.4 days when compared with vitamin C (105719). However, other clinical research in children has found no benefit with a specific E. purpurea product (Echinacin, Madaus AG) (4989,95653).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. It is unclear if oral echinacea reduces anxiety. Details: Preliminary clinical research shows that taking a specific E. angustifolia extract (ExtractumPharma ZRT) 40 mg once or twice daily for 7 days reduces anxiety scores on the State-Trait Anxiety Inventory scale when compared with placebo (20064,103233). This extract seems to be more effective in patients with high baseline anxiety scores (103233). A lower dose of 20 mg daily appears to be ineffective (20064). Conversely, a small clinical study in physically healthy adults with mild to moderate anxiety shows that taking the same E. angustifolia extract at doses of 20 or 40 mg twice daily for 6 weeks does not reduce anxiety when compared with placebo (106626).
• Athletic performance. It is unclear if oral echinacea improves athletic performance in healthy, recreationally active males. Details: Preliminary clinical research in healthy, recreationally active males shows that taking echinacea (Puritan's Pride) 2 grams four times daily for 28 days increases serum erythropoietin levels and maximal oxygen consumption (VO2max) during exercise tests (20066). However, two small clinical studies in endurance trained athletes and in non-athletes with high aerobic fitness show that taking E. purpurea 8 or 16 grams once daily for 35 days in combination with other ingredients (Biomedical Research Lab), or taking E. purpurea (Puritan's Pride) 8 grams daily for 42 days, has no effect on erythropoietin levels, VO2max, or aerobic capacity (95651,101593).
• Atopic dermatitis (eczema). Some evidence shows that an echinacea cream may be effective in mild disease, but it has not been compared to conventional treatments such as corticosteroids. Details: Preliminary clinical research in patients with mild atopic dermatitis shows that applying a cream containing echinacea (Linola Plus Cream, Dr. August Wolff GmbH & Co) 2-3 times daily for 12 weeks reduces symptoms such as erythema, edema, pruritus, and dryness when compared with a cream containing birch bark extract (Imlan Crème Pur, Birken AG). However, the echinacea product was no different to the comparator cream at the 4- and 8-week assessments, indicating that it might take up to 12 weeks to show benefit (97499).
• Attention deficit-hyperactivity disorder (ADHD). Although there has been interest in using oral echinacea for ADHD, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Burns. Although there has been interest in using topical echinacea for burns, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral echinacea for CFS, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Coronavirus disease 2019 (COVID-19). It is unclear if oral echinacea is beneficial for preventing or treating COVID-19. Details: A moderate-size open-label clinical study tested the effects of echinacea to prevent or treat respiratory viruses. This study of otherwise healthy adults in Bulgaria shows that taking echinacea extract (Echinaforce, A. Vogel AG) 2400 mg daily for cycles of 2, 2, and 1 months, with a 1-week break between each cycle, does not reduce symptomatic respiratory tract infections, including SARS-CoV-2, or respiratory virus detection overall when compared with usual care. However, echinacea extract does reduce the risk of a positive test for coronaviruses or SARS-CoV-2 by 48% and 63%, respectively. In patients who develop a symptomatic respiraA moderate-size open-label clinical study tested the effects of echinacea to prevent or treat respiratory viruses. This study of otherwise healthy adults in Bulgaria shows that taking echinacea extract (Echinaforce, A. Vogel AG) 2400 mg daily for cycles of 2, 2, and 1 months, with a 1-week break between each cycle, does not reduce symptomatic respiratory tract infections, including SARS-CoV-2, or respiratory virus detection overall when compared with usual care. However, echinacea extract does reduce the risk of a positive test for coronaviruses or SARS-CoV-2 by 48% and 63%, respectively. In patients who develop a symptomatic respiratory tract infection, this study also shows that taking the same echinacea extract 4000 mg daily for up to 10 days speeds viral clearance compared with usual care when all virus types were analyzed; however, clearance of SARS-CoV-2 was not improved. Echinacea may also reduce the number of days with a fever, but not other symptoms (111174). The validity of this study is limited by lack of blinding. Further, most patients were unvaccinated against COVID-19; it is unclear whether these results can be extrapolated to vaccinated patients.
• Genital herpes. It is unclear if oral echinacea is beneficial for genital herpes in patients with herpes simplex virus (HSV) type 1 or 2. Details: Some clinical research shows that a specific E. purpurea extract (Echinaforce, A. Vogel Bioforce AG) 800 mg orally twice daily for 6 months does not seem to prevent or reduce the frequency or duration of recurrent genital herpes in patients with herpes simplex virus (HSV) type 1 or 2 (7087).
• Gingivitis. Echinacea, in a mouth rinse or periodontal patch, has only been studied in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that using a mouth rinse containing echinacea, gotu kola, and elderberry (HM-302, Izun Pharmaceuticals) 15 mL three times daily for 14 days might prevent worsening of gingivitis when compared with a placebo rinse, but it produces only minimal improvement in symptoms (20069). Applying a periodontal patch containing echinacea, gotu kola, and elderberry (PerioPatch, Izun Pharmaceuticals) either as a single dose, or three times daily for 1 day then once daily for 2 days seems to reduce some measures of inflammation and gingivitis at some time points, but effects lack consistency (20068,20070).
• Herpes labialis (cold sores). Although there has been interest in using topical echinacea for herpes labialis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• HIV/AIDS. Although there has been interest in using oral echinacea for HIV/AIDS, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Human papillomavirus (HPV). Oral echinacea has only been studied in combination with other ingredients; its benefit when used alone is unclear. Details: Preliminary clinical research shows that taking a specific combination product containing echinacea, andrographis, grapefruit, papaya, pau d'arco, and cat's claw (Immune Act, Erba Vita SpA) three tablets daily for one month reduces the recurrence of anal condylomata in patients following surgical removal. After one month, the recurrence rate was about 4% in the echinacea group compared with 18% in the control group; after 6 months the recurrence rates were about 7% and 27%, respectively (20073). However, poor study methodology limits the validity of these findings.
• Influenza. Limited data suggest that oral echinacea may improve the response to influenza vaccine, and that a combination product containing echinacea may improve rates of recovery from influenza. Details: Preliminary clinical research shows that a taking a specific echinacea product (Monoselect Echinacea, PharmExtracta) 200 mg orally daily for 15 days, then 100 mg daily for 15 days, followed by 100 mg every other day for 60 days, might improve the response to influenza vaccine in people with chronic bronchitis or asthma (18226). Higher quality research is needed to confirm these results. Taking a specific combination product (Echinaforce Hot Drink, A. Vogel Bioforce AG), containing elderberry juice and extracts of E. purpurea above-ground parts and roots, 5 mL five times daily for 3 days, then three times daily for 7 days, improves rates of recovery and influenza-related respiratory complications similarly to oseltamivir 75 mg twice daily for 5 days (95650). However, due to the lack of a placebo group, it is unclear if both treatments were beneficial or if the outcomes represent the natural progression of influenza.
• Insect bite. It is unclear if topical homeopathy with a gel containing echinacea is beneficial for insect bite treatment. Oral echinacea has not been evaluated for this use. Details: Preliminary clinical research shows that using a homeopathic after-bite gel, containing echinacea, marsh Labrador tea, and stinging nettle, on affected areas does not reduce erythema or itching after a mosquito bite when compared with placebo (89235).
• Lichen planus. It is unclear if oral echinacea is beneficial for patients with this condition. Details: A small clinical study in adults with erosive oral lichen planus in Iran shows that taking a specific echinacea extract tablet (Immustim, Goldaru Corp.) 114 mg three times daily for 35 days decreases pain scores, number of lesions, and symptom severity when compared with placebo. However, all patients also used a mouthwash containing betamethasone, diphenhydramine, nystatin, and aluminum-magnesium suspension three times daily (111173).
• Malaria. Although there has been interest in using oral echinacea for malaria, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Migraine headache. Although there has been interest in using oral echinacea for migraine headache, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Otitis media. Oral echinacea does not seem to reduce the rate of recurrence of otitis media in young children, and may actually increase it. Details: Preliminary clinical research shows that taking a specific liquid extract of echinacea fresh roots and dried mature seeds, 0.5 mL three times daily for 3 days at the first sign of a common cold, followed by 0.25 mL three times daily for 7 days, does not prevent otitis media in children 1-5 years of age with a history of recurrent otitis media. In fact, the risk of an episode of otitis media during the 6 month follow-up seemed to increase by 59% in those taking echinacea when compared with placebo (20063).
• Psoriasis. Although there has been interest in using topical echinacea for psoriasis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Respiratory tract infections. It is unclear if oral echinacea is beneficial for patients with respiratory tract infections. Details: A large clinical study in adults with respiratory tract infections shows that using echinacea spray or taking echinacea lozenges 16,800 mg daily during days 1-3 and 2240-3360 mg daily afterward for up to 10 days does not improve time to recovery, symptom relief, or number of sick days when compared with echinacea tablets or drops at a prophylactic dose of 2400 mg daily for 10 days. However, the higher dose from days 1-3 is associated with faster viral clearance than the prophylactic dose (111540). The validity of these effects is limited by insufficient blinding and a lack of a placebo group.
• Rheumatoid arthritis (RA). Although there has been interest in using oral echinacea for RA, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Tonsillitis. Oral echinacea has been used with azithromycin to reduce relapses of recurrent tonsillitis in children. A throat spray containing echinacea has also been evaluated for tonsillitis-associated sore throat. It is unclear if echinacea is beneficial for either purpose. Details: Preliminary clinical research in children with recurrent tonsillitis shows that adding echinacea suspension, 250 mg root powder per 5 mL, orally 3 times daily for 10 consecutive days per month for 6 months, to azithromycin 10 mg/kg/day for 6 consecutive days per month for 6 months reduces the number of tonsillitis attacks when compared with azithromycin alone (104127). However, the study was not blinded and the number of tonsillitis episodes in both groups was very low. Other preliminary clinical research shows that applying a throat spray containing sage and echinacea whole plant extract every 2 hours up to 10 times daily for up to 5 consecutive days is as effective as a chlorhexidine-lidocaine spray in patients with sore throat due to acute pharyngitis or tonsillitis (20077).
• Tonsillopharyngitis. Oral echinacea has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized study in patients aged 12-75 years with acute tonsillopharyngitis shows that taking lozenges containing echinacea extract 800 mg and sage extract 5 times daily for 4 days reduces throat pain and tonsillopharyngitis symptoms when compared to baseline, both acutely within 90 minutes and after 4 days of treatment (111530). The validity of these effects is limited by a lack of a comparator group. It is unclear if these effects are due to echinacea, sage, or the combination.
• Upper respiratory tract infection (URTI). It is unclear if oral echinacea is beneficial for preventing or treating URTIs. Details: A moderate-size open-label clinical study tested the effects of echinacea to prevent or treat respiratory viruses. This study of otherwise healthy adults in Bulgaria shows that taking echinacea extract (Echinaforce, A. Vogel AG) 2400 mg daily for cycles of 2, 2, and 1 months, with a 1-week break between each cycle, does not reduce symptomatic respiratory tract infections, including SARS-CoV-2, or respiratory virus detection overall when compared with usual care. However, echinacea extract does reduce the risk of a positive test for coronaviruses or SARS-CoV-2 by 48% and 63%, respectively. In patients who develop a symptomatic respiratory tract infection, this study also shows that taking the same echinacea extract 4000 mg daily for up to 10 days speeds viral clearance compared with usual care when all virus types were analyzed; however, clearance of SARS-CoV-2 was not improved. Echinacea may also reduce the number of days with a fever, but not other symptoms (111174). The validity of this study is limited by lack of blinding. Further, most patients were unvaccinated against COVID-19; it is unclear whether these results can be extrapolated to vaccinated patients. Another large study in adults with URTIs shows that taking a combination product containing echinacea 1100-2200 mg, zinc, and vitamin C (EZC Pak) daily for 5 days reduces time to recovery by 1.4 days but does not reduce symptom severity when compared with placebo (111512). The validity of these effects is severely limited by multiple instances of selection bias. Additionally, it is unclear if these effects are due to echinacea, other ingredients, or the combination.
• Urinary tract infections (UTIs). Although there has been interest in using oral echinacea for UTIs, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Vaginal candidiasis. Although there has been interest in using oral echinacea for vaginal candidiasis, there is insufficient reliable information about the clinical effects of echinacea for this purpose.
• Warts. It is unclear if oral echinacea is beneficial for warts when used alone or in combination with other ingredients. Details: Preliminary clinical research shows that taking echinacea 600 mg orally once daily for up to 3 months does not clear common, plantar, or plain cutaneous warts any more effectively than placebo (20080). Other preliminary clinical research shows that taking an oral supplement containing echinacea with methionine, zinc, probiotics, antioxidants and immunostimulants for 6 months, in addition to using conventional topical therapy to treat cutaneous warts, seems to increase the rate of complete remission from 54% to 86% when compared with conventional therapy alone (20071). It is unclear if these effects are due to echinacea, other ingredients, or the combination.
• Water warts. It is unclear if oral echinacea is beneficial for water warts (molluscum contagiosum). Details: In children who have been successfully treated with curettage for molluscum contagiosum, taking a combination of E. angustifolia and E. purpurea orally daily for 2 months is associated with a relapse rate of about 39%, compared with a rate of 68% in a control group that received no oral treatment (104128). The validity of this finding is limited by the lack of a placebo control. E. angustifolia and E. purpurea were taken in doses of 200 mg each in children under 20 kg and 400 mg each in children over 20 kg. More evidence is needed to rate echinacea for these uses.

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POSSIBLY INEFFECTIVE

• Urine drug tests. Drinking water with goldenseal or adding goldenseal tea to urine does not appear to cause a false negative urine drug screen for amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencyclidine, or tetrahydrocannabinol (THC). Details: Goldenseal is often promoted to mask illicit drugs in the urine, but drinking one gallon of water with goldenseal or adding goldenseal tea to urine samples does not seem to cause a false negative immunoassay (EMIT and TDx) for cocaine, amphetamines, barbiturates, benzodiazepines, or opiates. It also does not produce a false negative for Microgenics CEDIA DAU assays for amphetamines, barbiturates, benzodiazepines, cocaine, opiates, phencyclidine, or THC (260,261,52599). Although adding goldenseal tea to urine samples at 15 grams per liter may produce a false-negative EMIT reading for the presence of THC, the adulteration is obvious due to a brownish color in the urine (52599). Some people also claim that goldenseal can cause a false positive on a drug screen. However, goldenseal does not seem to cause false positives for the fluorescent polarization immunoassay (FPIA) or thin-layer chromatography (TLC) assays for amphetamines, opiates, cocaine, methadone, or their metabolites (2590).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there has been interest in using topical goldenseal for acne, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Allergic rhinitis (hay fever). Although there has been interest in using oral goldenseal for allergic rhinitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Anorexia nervosa. Although there has been interest in using oral goldenseal for anorexia nervosa, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Atopic dermatitis (eczema). Although there has been interest in using topical goldenseal for atopic dermatitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral goldenseal for CFS, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Conjunctivitis. Although there has been interest in using goldenseal as an eye drop for conjunctivitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Dandruff. Although there has been interest in using topical goldenseal for dandruff, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Flatulence. Although there has been interest in using oral goldenseal for flatulence, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Gastritis. Although there has been interest in using oral goldenseal for gastritis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Gingivitis. Although there has been interest in using goldenseal as a mouthwash for gingivitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Hemorrhoids. Although there has been interest in using oral goldenseal for hemorrhoids, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Herpes labialis (cold sores). Although there has been interest in using topical goldenseal for herpes labialis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Menorrhagia. Although there has been interest in using oral goldenseal for menorrhagia, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Otitis media. Although there has been interest in using goldenseal as an ear drop for otitis media, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Peptic ulcers. Although there has been interest in using oral goldenseal for peptic ulcers, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Respiratory tract infections. Although there has been interest in using oral goldenseal for various respiratory tract infections, including influenza, pneumonia, rhinosinusitis, and the common cold, there is insufficient reliable information about the clinical effects of goldenseal for these conditions.
• Tinnitus. Although there has been interest in using goldenseal as an ear drop for tinnitus, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Urinary tract infections (UTIs). Although there has been interest in using oral goldenseal for UTIs, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Uveitis. Although there has been interest in using goldenseal as an eye drop for uveitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Vaginitis. Although there has been interest in using oral goldenseal for vaginitis, there is insufficient reliable information about the clinical effects of goldenseal for this purpose.
• Wound healing. Although there has been interest in using topical goldenseal for wound healing, there is insufficient reliable information about the clinical effects of goldenseal for this purpose. There is insufficient reliable information available about the effectiveness of goldenseal for its other uses.

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LIKELY EFFECTIVE

• Depression. Specific formulations of oral St. John's wort are effective for mild or moderate major depressive disorder. St. John's wort may also cause fewer side effects than certain conventional antidepressants. Details: Moderate quality meta-analyses and individual clinical trials show that St. John's wort extracts are more effective than placebo (76057,76140,76143,76271,89669,104036), and likely as effective as low-dose tricyclic antidepressants (6434,76143), tetracyclic antidepressants (76174), and selective serotonin reuptake inhibitors (SSRIs) (76143,76144,96551), including fluoxetine (Prozac) (3550,4897), sertraline (Zoloft) (6400), and paroxetine (Paxil) (13021) for treating depression. However, some of these studies have been critiqued for using lower doses of SSRIs than typical dosing in comparative studies (104037). St. John's wort also seems to have better tolerability and less gastrointestinal, neurologic, and sexual adverse effects than certain conventional antidepressants (104036). Taking St. John's wort extract improves mood and decreases anxiety, somatic symptoms, and insomnia related to mild to severe major depression (3550,4897,6400,13021,13157,76143,104036). Short-term response rates to St. John's wort appear to be between 65% and 100%; however, long-term, the response rates appear to range from 60% to 69% (13156). Most studies have evaluated St. John's wort in adults; however, there is also some evidence that taking St. John's wort 300-1800 mg daily might be effective for depression in children less than 17 years old (4538,10844,76110). There is some concern that St. John's wort may not be effective for severe major depressive disorder necessitating psychiatric care. Two studies in psychiatric care settings showed no benefit of using St. John's wort (5096,10843). Clinical guidelines from the American College of Physicians state that St. John's wort may be as effective and better tolerated than conventional antidepressants for mild to moderate depression (104037). Guidelines from The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce state that St. John's wort is recommended as monotherapy for mild to moderate forms of major depressive disorder (110318). There is no guarantee that people living in the United States can obtain St. John's wort preparations of similar potency and effectiveness as those used in clinical research (104037). The CANMAT Taskforce recommendation is for specific formulations of 3:1 to 7:1 extracts, standardized to approximately 0.2-0.3% hypericin and/or 5-6% hyperforin, in single or divided doses of 600 mg to 1800 mg daily (110318). Most studies have used St. John's wort extracts standardized to hypericin content, usually 0.3%, but extracts standardized to 1% to 4% hyperforin also seem to be effective. Extracts containing hypericin 0.2% to 0.3%, including LI 160 (Lichtwer Pharma) and Remotiv (Zeller) have most often been studied in doses of 300 mg three times daily for up to 6 weeks, or 250 mg twice daily for up to 6 weeks. Extracts containing 3% to 6% hyperforin, including Movana (Pharmaton) and WS 5570 (Schwabe Pharmaceuticals) have most often been studied in doses of 300-600 mg three times daily for 6-26 weeks (761,4538,4630,104036).

POSSIBLY EFFECTIVE

• Menopausal symptoms. Oral St. John's wort seems to be beneficial for patients with menopausal symptoms. Details: Most clinical research shows that taking St. John's wort as a single supplement can reduce menopausal symptoms. A meta-analysis of small clinical trials in menopausal adults shows that taking St. John's wort up to 900 mg daily for up to 16 weeks, alone or in combination with other herbs, reduces frequency and severity of hot flashes when compared with placebo (95510). Some research also suggests that St. John's wort might improve quality of life and psychological symptoms when compared with placebo (76043,76146,89666,95510). St. John's wort has also shown benefit when used in combination with black cohosh (Remifemin Plus, Schaper & Brummer GmbH & Co. KG; Gynoplus, Jin-Yang Pharm; Feramin Q, Dongkook Pharm) (15037,15893,35853,95510), and with Vitex agnus-castus (41482).
• Somatic symptom disorder. Oral St. John's wort seems to be beneficial for patients with somatoform disorder. Details: Two clinical trials in patients with somatoform disorders shows that taking a specific standardized St. John's wort extract (LI 160, Lichtwer Pharma) 600 mg daily seems to reduce symptoms of somatization disorder by 45% after 6 weeks of treatment when compared with placebo (9476,76089).

POSSIBLY INEFFECTIVE

• Burning mouth syndrome. Oral St. John's wort does not appear to reduce pain from burning mouth syndrome. Details: A small clinical study in patients with burning mouth syndrome shows that taking St. John's wort 300 mg (standardized to hypericin 0.3% and hyperforin 3.0%) three times daily for 12 weeks does not alleviate pain when compared to placebo (76133).
• Hepatitis C. St. John's wort contains hypericin. Synthetic hypericin has been studied and shown to be ineffective as an oral drug for hepatitis C. Details: A small clinical study in patients with chronic hepatitis C virus (HCV) infection shows that giving synthetic hypericin 0.05-0.1 mg/kg orally daily does not seem to be effective for reducing viral load and may be unsafe due to the risk for phototoxic reactions (4631).
• HIV/AIDS. St. John's wort contains hypericin. Synthetic hypericin has been studied and shown to be ineffective as an oral and intravenous drug for HIV. Details: A small clinical study in adults infected with HIV shows that giving synthetic hypericin 0.25-0.5 mg/kg, either intravenously 2-3 times weekly or orally every day, as an antiretroviral agent does not seem to be effective and may be unsafe due to the risk for phototoxic reactions, which occurred in about 50% of patients (206).
• Irritable bowel syndrome (IBS). Oral St. John's wort does not seem to improve symptoms in patients with IBS. Details: A small clinical study shows that taking a specific St. John's wort extract (St. John's Wort Extract Extra Strength, Enzymatic Therapy) 450 mg twice daily is no more effective than placebo for reducing symptoms of IBS after 12 weeks of treatment. In fact, patients taking placebo had improved symptoms compared to St. John's wort (16893).
• Peripheral neuropathy. Oral St. John's wort does not seem to relieve pain in patients with peripheral neuropathy. Details: A small clinical study in diabetic and non-diabetic patients with polyneuropathy shows that taking St. John's wort containing 0.9 mg hypericin orally daily for 5 weeks does not seem to relieve most measures of pain when compared with placebo (7047).
• Social anxiety disorder. Oral St. John's wort does not seem to be beneficial for patients with social anxiety disorder. Details: A small clinical study shows that taking St. John's wort 600-1800 mg daily for 12 weeks does not improve social phobia or social anxiety disorder when compared with placebo (76101).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. It is unclear if topical St. John's wort is beneficial for acne. Details: A small clinical trial in patients with mild to moderate acne treated with photodynamic therapy shows that topical application with 1.5 mL of a St. John's wort 0.5% extract (DR-Light complex; Genicos Co., Ltd, Cheongju, Korea) for 10 minutes for four weekly sessions reduces acne lesion count as effectively as treatment with indole-3-acetic acid (110327).
• Anxiety. Although there is interest in using oral St. John's wort for anxiety, there is insufficient reliable information about the clinical effects of St. John's wort for this condition.
• Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral St. John's wort is beneficial for improving symptoms in children with ADHD. Details: A small clinical study in children ages 6-17 years with ADHD shows that taking a specific St. John's wort extract standardized to 0.3% hypericin, 300 mg three times daily for 8 weeks, does not improve symptoms such as inattentiveness when compared with placebo (17986).
• Brain tumor. St. John's wort contains hypericin. Synthetic hypericin has been studied as an oral drug for malignant brain tumors, with unclear benefit. Details: A small clinical study in patients with malignant gliomas shows that taking synthetic hypericin 0.05-0.5 mg/kg daily orally for up to 3 months was associated with stable disease in 7 of 42 patients and partial response in 2 of 42 patients (76160). However, it is unclear how these outcomes would compare with historical controls or a prospectively enrolled control group.
• Chronic fatigue syndrome (CFS). Although there is interest in using oral St. John's wort for CFS, there is insufficient reliable information about the clinical effects of St. John's wort for this condition.
• Crigler-Najjar syndrome type 2. It is unclear if oral St. John's wort is beneficial for patients with this condition. Details: Crigler-Najjar syndrome type 2 is a rare genetic disorder characterized by the accumulation of bilirubin in the body. One case report of a 24 year-old female with this condition shows that taking St. John's wort (Jarsin LI160, Vifor SA) 300 mg three times daily by mouth for two 8-week periods 18 months apart decreases bilirubin levels by 34%, reduces jaundice, and improves fatigue (95509).
• Fibromyalgia. Although there is interest in using oral St. John's wort for fibromyalgia, there is insufficient reliable information about the clinical effects of St. John's wort for this condition.
• Genital herpes. Topical St. John's wort has only been evaluated in combination with copper sulfate; its effect when used alone is unclear. Details: A clinical study in patients with herpes simplex virus 1 (HSV-1) or 2 (HSV-2) shows that applying a single dose of a specific topical product (Dynamiclear, Global Herbal Supplies Pty Ltd), which contains St. John's wort 0.1% and copper sulfate pentahydrate 5%, helps reduce symptoms such as stinging, burning, erythema, and pain. In fact, the combination product appears to reduce erythema, itching, and pain more than applying acyclovir 5% (Zovirax, Glaxo Smith Kline) five times daily for 7 days (76164).
• Herpes labialis (cold sores). Topical St. John's wort has only been evaluated in combination with copper sulfate; its effect when used alone is unclear. Details: A clinical study in patients with herpes simplex virus 1 (HSV-1) or 2 (HSV-2) shows that applying a single dose of a specific topical product (Dynamiclear, Global Herbal Supplies Pty Ltd), which contains St. John's wort 0.1% and copper sulfate pentahydrate 5%, helps reduce symptoms such as stinging, burning, erythema, and pain. In fact, the combination product appears to reduce erythema, itching, and pain more than applying acyclovir 5% (Zovirax, Glaxo Smith Kline) five times daily for 7 days (76164).
• Mastitis. It is unclear if topical St. John's wort is beneficial for granulomatous mastitis. Details: In patients with idiopathic granulomatous mastitis, persistent or intractable skin lesions may remain after treatment with oral steroids and antibiotics. Preliminary clinical research shows that topical application with St. John's wort oil for two minutes twice daily for 6 weeks reduces the severity of skin lesions in patients with persistent lesions following treatment. After treatment, the success rate, based on clearance or remaining mild symptoms, was 94.1% (110326).
• Memory. It is unclear if oral St. John's wort is beneficial for improving memory in healthy people. Details: A small clinical study in healthy adults shows that taking a specific supplement (Remotiv, Zeller) containing St. John's wort 250 mg, standardized to 0.5 mg of hypericin, by mouth as a single dose, seems to improve short-term memory when compared with baseline. In contrast, the same product containing a higher dose of St. John's wort, 500 mg, seems to worsen memory when compared with baseline (100245). The validity of this finding is limited by the lack of a control group.
• Migraine headache. It is unclear if oral St. John's wort is beneficial for reducing migraine headache. Details: A small low quality clinical study in patients with migraines suggests that adding a specific St. John's wort product (Perforan, Godaru) 160 mg three times daily to sodium valproate 400 mg daily might modestly improve migraine intensity, but not migraine frequency, when compared with sodium valproate alone (89667).
• Obsessive-compulsive disorder (OCD). It is unclear if oral St. John's wort is beneficial for reducing OCD symptoms. Details: There is conflicting evidence about the effectiveness of St. John's wort for OCD. A small open-label study suggests that taking a specific St. John's wort extract standardized to 0.3% hypericin (Alterra, Upsher-Smith Laboratories) 450 mg twice daily for 12 weeks might improve symptoms of OCD when compared to baseline (5075). The validity of this finding is limited by the lack of a control group. A small, higher quality clinical study using a different St. John's wort extract (LI 160, Lichtwer Pharma AG) 600-1800 mg daily for 12 weeks shows that it does not improve symptoms of OCD when compared with placebo (14417). However, this study excluded patients with concomitant depression, so it's unclear if St. John's wort might improve OCD symptoms in patients with depression.
• Polycystic ovary syndrome (PCOS). Oral St. John's wort has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study shows that taking three tablets containing St. John's wort, licorice root, Ceylon cinnamon, levant berry, peony, and Tribulus daily for 3 months, in addition to lifestyle changes, improves oligomenorrhea by 33% and quality of life by 30% when compared with lifestyle changes alone in adults with PCOS (97216). It is unclear if these effects are due to St. John's wort, other ingredients, or the combination.
• Premenstrual syndrome (PMS). It is unclear if oral St. John's wort is beneficial for patients with PMS. Details: There is conflicting evidence on the effects of St. John's wort for treating PMS, although most evidence suggests benefit. A small clinical study shows that taking a specific St. John's wort extract standardized to contain 0.18% hypericin and 3.38% hyperforin (LI 160, Lichtwer Pharma AG) 450 mg twice daily for two menstrual cycles reduces physical and behavioral PMS symptoms, but not mood or pain, when compared with placebo (76150). Another clinical study shows that taking St. John's wort extract containing hypericin 1.36 mg daily for two menstrual cycles can reduce symptoms of PMS, including anxiety, depression, forgetfulness, crying, headache, and fatigue, when compared with placebo (76159). However, one clinical study shows that taking St. John's wort 600 mg (standardized to contain 1.8 mg of hypericin) does not reduce anxiety or other PMS symptoms when compared with placebo (76104). The conflicting results may be due to differences in St. John's wort formulations and dosages.
• Psoriasis. It is unclear if topical St. John's wort improves symptoms in patients with plaque psoriasis. Details: A small clinical study in patients with mild or moderate plaque psoriasis shows that applying an ointment containing St. John's wort extract 5% twice daily to one side of the body for 4 weeks modestly decreases the severity, thickness, and degree of erythema of psoriasis plaques when compared with applying placebo ointment to the other side of the body (95940).
• Seasonal affective disorder (SAD). It is unclear if oral St. John's wort is beneficial for patients with SAD. Details: Preliminary clinical research shows that St. John's wort extract improves symptoms associated with SAD, including anxiety, decreased libido, and sleep disturbances, when compared with baseline. It may be beneficial when used alone or in combination with light therapy (9686,76175). However, the validity of these findings is limited by the lack of a comparator group.
• Scleroderma. Topical St. John's wort has only been evaluated in combination with neem oil; its effect when used alone is unclear. Details: A small observational study in patients with systemic sclerosis has found that topical application of a specific cream (Holoil, RI.MOS. SRL) containing St. John's wort and neem oil is associated with improved healing, decreased pain, and reduced need for surgical interventions and antibiotics when compared with a control group (102867). It is unknown if these effects are due to St. John's wort, neem, or the combination. Additionally, the validity of these results is limited by a lack of randomization, blinding, and placebo-control.
• Smoking cessation. It is unclear if oral St. John's wort is beneficial for patients trying to quit smoking. Details: A small clinical study in cigarette smokers shows that taking a specific St. John's wort extract (LI-160, Lichtwer Pharma US) 300 mg once or twice daily, starting 1 week before and continuing for 3 months after quitting smoking, is associated with a continuous abstinence rate of 18% at 3 months and 0% at 12 months, suggesting a lack of benefit (14481).
• Wound healing. Topical St. John's wort seems to improve wound healing and wound-related pain for certain types of surgery. Details: A clinical study in patients who have had a Cesarean section shows that applying ointment containing St. John's wort extract 20% three times a day for 16 days improves wound healing and reduces scar formation when compared with placebo ointment (17225). Preliminary clinical research in patients who have had impacted third molars removed shows that using a mouthwash, prepared by macerating the above ground parts of St. John's wort in virgin olive oil, for 60 days is as effective as chlorhexidine gluconate plus benzydamine hydrochloride mouthwash for improving periodontal healing, and reducing swelling, pain, and infectious complications. However, it was also as effective as plain virgin olive oil, suggesting that St. John's wort did not provide additional benefit. 15 mL of each mouthwash was swished for 30 seconds 3 times daily for 7 days (104957). St. John's wort has also been evaluated in combination with other ingredients. A moderate-sized clinical study in adults with dehisced post-surgical wounds shows that applying a specific aerosol product (1PWD, Kerecis AG) containing St. John's wort and neem oil to wounds during dressing changes does not improve wound healing scores at day 28 but may reduce pain scores when compared with silver-based dressings (alginates or polyurethane foam) (111592). However, this study may have been inadequately powered to detect a difference between groups. It is also unclear if these effects are due to St. John's wort, neem oil, or the combination.
• Tinnitus. St. John's wort has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small study in adults with tinnitus shows that taking St. John's wort 600 mg and ginkgo biloba daily for 12 weeks does not suppress tinnitus or improve tinnitus-related handicap when compared with ginkgo biloba monotherapy (111513). More evidence is needed to rate St. John's wort for these uses.

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POSSIBLY UNSAFE ...when used orally. Boneset can cause severe diarrhea and vomiting. Hepatotoxic pyrrolizidine alkaloids (PAs) are common in this genus of plants; however, the alkaloids in boneset have not been adequately characterized to determine their toxic potential (12842,102557).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally. Hepatotoxic PAs are common in this genus of plants; however, the alkaloids in boneset have not been adequately characterized to determine their toxic potential (12842,102557). Hepatotoxic PAs might be teratogenic; avoid using.

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LIKELY SAFE ...when used orally and appropriately, short-term. Various liquid extracts of Echinacea purpurea have been used safely for up to 10 days, including EchinaGuard (Madaus AG) 20 drops every 2 hours for 1 day, then three times daily (10320), or Echinilin (Inovobiologic Inc.) 40 mL in divided doses for 1 day, then 15 mL in divided doses daily thereafter (12355,20062). Other liquid extracts have been used safely for relatively longer periods, including Echinaforce (A. Vogel Bioforce AG) 2.4 grams daily for 4 months or 1.6 grams daily for 6 months (7087,18225), and Echinacin (Madaus AG) 5 mL twice daily for 10 days, or 4 mL twice daily for 8 weeks (3282,10802). Specific solid dosage forms of echinacea that have been used safely for up to 10 days include Echinacea purpurea above-ground parts (EchinaFresh, Enzymatic Therapy) 300 mg daily (11970), and mixtures of Echinacea purpurea and Echinacea angustifolia herb in divided doses of 6 grams to 10.5 grams for 1 day then 3 grams to 5.1 grams daily (10800,17519,20059). A specific Echinacea angustifolia extract (ExtractumPharma ZRT) has also been used with apparent safety at a dose of 40 mg once or twice daily for up to 7 days (20064,103233). An Echinacea purpurea product (Natures Resource) has been used safely at a dose of 1.8 grams daily for 8 weeks (17521), and echinacea (Puritan's Pride) has been used safely at 8 grams daily for 28 days (20066).

POSSIBLY SAFE ...when used topically, short-term. A specific cream (Linola Plus Cream, Dr. August Wolff GmbH & Co.) containing echinacea extract (WO 3260) has been applied to the skin safely 2-3 times daily for up to 12 weeks (97499). There is insufficient reliable evidence about the safety of echinacea when used parenterally.

CHILDREN: POSSIBLY SAFE
when used orally, short-term. Some clinical research shows that an extract of the above-ground parts of Echinacea purpurea (EC31J2, Echinacin Saft, Madaus AG) in a dose of 3.75 mL twice daily (for ages 2 years to 5 years) or 7.5 mL twice daily (for ages 6 years to 11 years) is safe when used for up to 10 days (4989). However, about 7% of children experienced a rash after taking echinacea, which might have been caused by an allergic reaction (4989). There is concern that allergic reactions could be severe in some children. The Medicines and Healthcare Products Regulatory Agency in the United Kingdom recommends against the use of oral echinacea products in children under 12 years of age due to this risk of allergic reaction (18207). In contrast, another clinical study in children 4-12 years old shows that a specific Echinacea purpurea product (Echinaforce Junior, A. Vogel) does not cause allergic or urticarial reactions more frequently than vitamin C (105719).

PREGNANCY: POSSIBLY SAFE
when used orally, short-term. There is preliminary evidence that mothers can safely use echinacea in the form of E. purpurea or E. angustifolia solid dosage forms, 250-1000 mg daily, or tinctures, up to 30 drops daily, for 5 days to 7 days during the first trimester without adversely affecting the fetus (7056,13418,15123). There is insufficient reliable information available about the safety of echinacea when used for longer than 7 days.

LACTATION:
Insufficient reliable information available; avoid using.

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POSSIBLY SAFE ...when used orally and appropriately as a single dose (260,261). There is insufficient reliable information available about the safety of goldenseal when used as more than a single dose.

CHILDREN: LIKELY UNSAFE
when used orally in newborns. The berberine constituent of goldenseal can cause kernicterus in newborns, particularly preterm neonates with hyperbilirubinemia (2589).

PREGNANCY: LIKELY UNSAFE
when used orally. Berberine is thought to cross the placenta and may cause harm to the fetus. Kernicterus has developed in newborn infants exposed to goldenseal (2589).

LACTATION:
LIKELY UNSAFE when used orally. Berberine and other harmful constituents can be transferred to the infant through breast milk (2589). Use during lactation can cause kernicterus in the newborn and several resulting fatalities have been reported (2589).

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LIKELY SAFE ...when used orally and appropriately. St. John's wort extracts in doses up to 900 mg daily seem to be safe when used for up to 12 weeks (3547,3550,4835,5096,6400,6434,7047,13021,13156,13157)(14417,76143,76144,89666,89669,95510). Some evidence also shows that St. John's wort can be safely used for over one year (13156,13157,76140), and may have better tolerability than selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) (4897,76153,76143,104036).

POSSIBLY SAFE ...when used topically and appropriately. St. John's wort 0.5% extract seems to be safe when used once weekly for 4 weeks (110327). St. John's wort oil has been used with apparent safely twice daily for 6 weeks (110326). However, topical use of St. John's wort can cause photodermatitis with sun exposure (110318).

POSSIBLY UNSAFE ...when used orally in large doses. St. John's wort extract can be unsafe due to the risk of severe phototoxic skin reactions. Taking 2-4 grams of St. John's wort extract (containing hypericin 5-10 mg) daily appears to increase the risk of photosensitivity (758,4631,7808).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Preliminary population research has found that taking St. John's wort while pregnant is associated with offspring that develop neural tube, urinary, and cardiovascular malformations. Subgroup analyses suggest that these risks may be higher when taking St. John's wort during the first trimester when compared with the second or third trimester. However, more research is needed to confirm these findings (106052). Animal-model research also shows that constituents of St. John's wort might have teratogenic effects (9687,15122). Until more is known, St. John's wort should not be taken during pregnancy.

LACTATION: POSSIBLY UNSAFE
when used orally. Nursing infants of mothers who take St. John's wort have a greater chance of experiencing colic, drowsiness, and lethargy (1377,15122,22418); avoid using.

CHILDREN: POSSIBLY SAFE
when used orally, and appropriately, short-term. St. John's wort extracts in doses up to 300 mg three times daily seem to be safe when used for up to 8 weeks in children aged 6-17 years (4538,17986,76110).

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(Read more about BONESET)

CAFFEINE Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Echinacea can increase plasma levels of caffeine by inhibiting its metabolism.  Details Echinacea seems to increase plasma concentrations of caffeine by around 30% (12155). This is likely due to inhibition of cytochrome P450 1A2 (CYP1A2) by echinacea.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Echinacea might inhibit the metabolism of CYP1A2 and increase plasma levels of some drugs.  Details Echinacea appears to inhibit CYP1A2 enzymes in humans. Additionally, echinacea seems to increase plasma concentrations of caffeine, a CYP1A2 substrate, by around 30% (12155). Theoretically, echinacea might increase levels of other drugs metabolized by CYP1A2.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Echinacea may induce hepatic CYP3A4 and inhibit intestinal CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.  Details Several clinical trials have shown that taking echinacea for up to one month does not significantly affect the metabolism of various CYP3A4 substrates, including midazolam, docetaxel, etravirine, lopinavir-ritonavir, and darunavir-ritonavir (13712,48618,88164,88165). However, other clinical research shows that echinacea may increase the clearance of midazolam, suggesting that echinacea might induce CYP3A4 (48618). The discrepancy is thought to be due to differing effects of echinacea on intestinal versus hepatic CYP3A4 enzymes. Echinacea appears to induce hepatic CYP3A4 but inhibit intestinal CYP3A4 (12155). In some cases, these effects might cancel each other out, but in others, drug levels may be increased or decreased depending on the level of effect at hepatic and intestinal sites. The effect of echinacea on CYP3A4 activity may differ depending on the CYP3A4 substrate (6450,11026,88162,88167).

DARUNAVIR (Prezista) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of darunavir; however, a small clinical study found no effect.  Details Darunavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but administration of an E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg four times daily for 14 days did not affect darunavir/ritonavir pharmacokinetics in 15 HIV-infected patients (88163,93578).

DOCETAXEL (Taxotere) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of docetaxel; however, a small clinical study found no effect.  Details Docetaxel is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea whole plant extract (Echinaforce, A. Vogel Biopharma AG) 20 drops three times daily for 2 weeks did not alter the pharmacokinetics of docetaxel in one clinical study (88164).

ETOPOSIDE (VePesid) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Echinacea may increase levels of etoposide.  Details In one report, concomitant use of etoposide and echinacea was associated with more severe thrombocytopenia than the use of etoposide alone, suggesting inhibition of etoposide metabolism (20082). Etoposide is a cytochrome P450 3A4 (CYP3A4) substrate. Echinacea has variable effects on CYP3A4, but some studies have reported inhibition of the enzyme (6450,11026,12155,88162,88167).

ETRAVIRINE (Intelence) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of etravirine; however, a small clinical study found no effect.  Details Etravirine is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg three times daily for 14 days did not alter the pharmacokinetics of etravirine in HIV-infected patients (88165,93578).

IMMUNOSUPPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Echinacea has immunostimulant activity which may interfere with immunosuppressant therapy.  Details Theoretically, echinacea may interfere with immunosuppressant therapy because of its immunostimulant activity (3279,6388,6389,12639).

LOPINAVIR/RITONAVIR (Kaletra) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, echinacea may interfere with the metabolism of lopinavir; however, a small clinical study found no effect.  Details Lopinavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but taking E. purpurea (Echinamide, Natural Factors Nutritional Products, Inc.) 500 mg three times daily for 14 days did not alter the pharmacokinetics of lopinavir/ritonavir in healthy volunteers (48618,93578).

MIDAZOLAM (Versed) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B Theoretically, echinacea may increase the metabolism of intravenous midazolam.  Details Echinacea induces hepatic CYP3A4 and might decrease plasma levels of midazolam by about 20%, reducing the effectiveness of intravenous midazolam (12155). Echinacea also appears to inhibit intestinal CYP3A4, which could theoretically increase the bioavailability of oral midazolam. This may cancel out the decrease in availability caused by induction of hepatic CYP3A4, such that overall plasma levels after oral administration of midazolam are not affected by echinacea.

WARFARIN (Coumadin) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B Echinacea seems to increase the clearance of warfarin, although the effect may not be clinically significant.  Details Preliminary clinical research in healthy male volunteers suggests that taking echinacea increases the clearance of the active S-isomer of warfarin after a single dose of warfarin, but there was not a clinically significant effect on the INR (20083).

(Read more about ECHINACEA)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.  Details Goldenseal contains berberine. In vitro and animal research shows that berberine can inhibit platelet aggregation (33660,33694). However, this effect has not been reported in humans.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the risk of hypoglycemia when used with antidiabetes drugs.  Details Goldenseal contains berberine. Clinical research shows that berberine can lower blood glucose levels (20579,34247,34265,34282). However, this effect has not been reported with goldenseal.

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the risk of hypotension when taken with antihypertensive drugs.  Details Goldenseal contains berberine. Animal research shows that berberine can have hypotensive effects (33692,34308). Also, an analysis of clinical research shows that taking berberine in combination with amlodipine can lower systolic and diastolic blood pressure when compared with amlodipine alone (91956). However, this effect has not been reported with goldenseal.

CNS DEPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the sedative effects of CNS depressants.  Details Goldenseal contains berberine. Animal research shows that berberine can have sedative effects (13519,33650,33664,33692). However, this effect has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2C9.  Details In vitro research shows that goldenseal root extract can modestly inhibit CYP2C9. This effect may be due to its alkaloid constituents, hydrastine and berberine (21117). However, this effect has not been reported in humans.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Goldenseal might increase serum levels of drugs metabolized by CYP2D6.  Details Clinical and in vitro research shows that goldenseal can significantly inhibit CYP2D6 enzymes, potentially increasing levels of drugs metabolized by CYP2D6 (13536,16848,35907).

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2E1.  Details In vitro research shows that goldenseal root extract can inhibit the activity of CYP2E1 (94140). However, this effect has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Goldenseal might increase serum levels of drugs metabolized by CYP3A4.  Details Most clinical and in vitro research shows that goldenseal inhibits CYP3A4 enzyme activity and increases serum levels of CYP3A4 substrates, such as midazolam (6450,13536,21117,91740,111725). However, in one small clinical study, goldenseal did not affect the levels of indinavir, a CYP3A4 substrate, in healthy volunteers (10690,93578). This is likely due to the fact that indinavir has a high oral bioavailability, making it an inadequate probe for CYP3A4 interactions (13536,91740) and/or that it is primarily metabolized by hepatic CYP3A, while goldenseal has more potential to inhibit intestinal CYP3A enzyme activity (111725). Both goldenseal extract and its isolated constituents berberine and hydrastine inhibit CYP3A, with hydrastine possibly having more inhibitory potential than berberine (111725).

DEXTROMETHORPHAN (Robitussin DM, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of dextromethorphan.  Details Goldenseal contains berberine. A small clinical study shows that berberine can inhibit cytochrome P450 2D6 (CYP2D6) activity and reduce the metabolism of dextromethorphan (34279).

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Goldenseal might increase serum levels of digoxin, although this effect is unlikely to be clinically significant.  Details Clinical research shows that goldenseal modestly increases digoxin peak levels by about 14% in healthy volunteers. However, goldenseal does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC) (15132). This suggests that goldenseal does not cause a clinically significant interaction with digoxin. Digoxin is a P-glycoprotein substrate. Some evidence suggests that goldenseal constituents might affect P-glycoprotein; however, it is unclear whether these constituents inhibit or induce P-glycoprotein.

LOSARTAN (Cozaar) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might decrease the conversion of losartan to its active form.  Details Goldenseal contains berberine. A small clinical study shows that berberine inhibits cytochrome P450 2C9 (CYP2C9) activity and reduces the metabolism of losartan (34279). However, this effect has not been reported with goldenseal.

METFORMIN (Glucophage) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might reduce blood levels of metformin.  Details In vitro research shows that goldenseal extract decreases the bioavailability of metformin, likely by interfering with transport, intestinal permeability, or other processes involved in metformin absorption. It is unclear which, if any, of metformin's transporters are inhibited by goldenseal. Goldenseal does not appear to alter the clearance or half-life of metformin (105764).

OSELTAMIVIR (Tamiflu) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might reduce the therapeutic effects of oseltamivir by decreasing its conversion to its active form.  Details In vitro evidence suggests that goldenseal reduces the formation of the active compound from the prodrug oseltamivir (105765). The mechanism of action and clinical relevance is unclear.

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Theoretically, goldenseal might increase or decrease serum levels of P-glycoprotein (P-gp) substrates.  Details There is conflicting evidence about the effect of goldenseal on P-gp. In vitro research suggests that berberine, a constituent of goldenseal, modestly inhibits P-gp efflux. Other evidence suggests that berberine induces P-gp. In healthy volunteers, goldenseal modestly increases peak levels of the P-gp substrate digoxin by about 14%. However, it does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC) (15132). This suggests that goldenseal is not a potent inhibitor of P-gp-mediated drug efflux. Until more is known, goldenseal should be used cautiously with P-gp substrates.

PENTOBARBITAL (Nembutal) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase the sedative effects of pentobarbital.  Details Animal research shows that berberine, a constituent of goldenseal, can prolong pentobarbital-induced sleeping time (13519). However, this effect has not been reported with goldenseal.

TACROLIMUS (Prograf) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenseal might increase serum levels of tacrolimus.  Details Goldenseal contains berberine. In a 16-year-old patient with idiopathic nephrotic syndrome who was being treated with tacrolimus 6.5 mg twice daily, intake of berberine 200 mg three times daily increased the blood concentration of tacrolimus from 8 to 22 ng/mL. Following a reduction of tacrolimus dosing to 3 mg daily, blood levels of tacrolimus decreased to 12 ng/mL (91954).

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ALPRAZOLAM (Xanax) Interaction Rating = Major Do not take this combination. Severity = Moderate •  Occurrence = Likely •  Level of Evidence = B St. John's wort increases the clearance of alprazolam and decreases its effects.  Details Alprazolam, which is used as a probe for cytochrome P450 3A4 (CYP3A4) activity, has a two-fold increase in clearance when given with St. John's wort. St. John's wort reduces the half-life of alprazolam from 12.4 hours to 6 hours (10830).

AMBRISENTAN (Letairis) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Probable •  Level of Evidence = B St. John's wort may increase the clearance of ambristentan and decrease its effects.  Details Clinical research in healthy volunteers shows that taking St. John's wort 900 mg daily decreases the area under the concentration-time curve of ambrisentan 5 mg by 17% to 26%. Ambrisentan clearance was increased by 20% to 35% depending on CYP2C19 genotype. However, these small changes are unlikely to be clinically significant (99511).

AMINOLEVULINIC ACID Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D St. John's wort might have additive phototoxic effects with aminolevulinic acid.  Details Concomitant use with St. John's wort extract may cause synergistic phototoxicity. Delta-aminolevulinic acid can cause a burning erythematous rash and severe swelling of the face, neck, and hands when taken with St. John's wort (9474).

BOCEPREVIR (Victrelis) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = B St. John's wort might decrease the levels and clinical effects of boceprevir.  Details Boceprevir increases the maximum concentration and concentration at 8 hours of the St. John's wort constituent, hypericin, by approximately 30%. However, St. John's wort does not significantly change the area under the concentration-time curve or maximum plasma concentration of boceprevir 800 mg three times daily in healthy adults (95507,96552).

BUPROPION (Wellbutrin) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B St. John's wort might reduce the levels and effects of bupropion.  Details Clinical research shows that taking St. John's wort 325 mg three times daily for 14 days along with bupropion reduces the area under the concentration-time curve by approximately 14% and increases the clearance of bupropion by approximately 20%. This effect is attributed to the induction of cytochrome P450 2B6 (CYP2B6) by St. John's wort (89662).

CLOPIDOGREL (Plavix) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B St. John's wort might increase the levels and effects of clopidogrel.  Details Taking St. John's wort with clopidogrel seems to increase the activity of clopidogrel. In clopidogrel non-responders, taking St. John's wort seems to induce metabolism of clopidogrel to its active metabolite by cytochrome P450 enzymes 3A4 and 2C19. This leads to increased antiplatelet activity (13038,89671,96552). Theoretically, this might lead to an increased risk of bleeding in clopidogrel responders.

CLOZAPINE (Clozaril) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D St. John's wort might decrease the levels and clinical effects of clozapine.  Details A case report describes a female with schizophrenia controlled on clozapine who had a return of symptoms when she started taking St. John's wort. The plasma concentration of clozapine was reduced, likely because its clearance was increased due to induction of the cytochrome P450 enzymes 3A4, 1A2, 2C9, and 2C19 by St. John's wort (96552).

CONTRACEPTIVE DRUGS Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B St. John's wort increases the clearance of contraceptive drugs and reduces their clinical effects.  Details Females taking St. John's wort and oral contraceptives concurrently should use an additional or alternative form of birth control. St. John's wort can decrease norethindrone and ethinyl estradiol levels by 13% to 15%, resulting in breakthrough bleeding, irregular menstrual bleeding, or unplanned pregnancy (11886,11887,13099). Bleeding irregularities usually occur within a week of starting St. John's wort and regular cycles usually return when St. John's wort is discontinued. Unplanned pregnancy has occurred with concurrent use of oral contraceptives and St. John's wort extract (9880). St. John's wort is thought to induce the cytochrome P450 1A2 (CYP1A2), 2C9 (CYP2C9), and 3A4 (CYP3A4) enzymes, which are responsible for metabolism of progestins and estrogens in contraceptives (1292,7809,9204).

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B St. John's wort reduces the levels and clinical effects of cyclosporine.  Details Concomitant use can decrease plasma cyclosporine levels by 30% to 70% (1234,4826,4831,4834,7808,9596,10628,96552). Using St. John's wort with cyclosporine in patients with heart, kidney, or liver transplants can cause subtherapeutic cyclosporine levels and acute transplant rejection (1234,1293,1301,6112,6435,7808,9596). This interaction has occurred with a St. John's wort extract standardized to 0.3% hypericin and dosed at 300-600 mg per day (6435,10628). Withdrawal of St. John's wort can result in a 64% increase in cyclosporine levels (1234,4513,4826,4831,4834). St. John's wort induces cytochrome P450 3A4 (CYP3A4) and the multi-drug transporter, P-glycoprotein/MDR-1, which increases cyclosporine clearance (1293,1340,9204,9596).

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B St. John's wort may increase the metabolism and reduce the levels of CYP1A2 substrates.  Details Clinical research shows that St. John's wort induces CYP1A2, but to a lesser extent than CYP3A4 (9204,10848,76163).

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B St. John's wort may increase the metabolism and reduce the levels of CYP2B6 substrates.  Details Clinical research shows that taking St. John's wort 325 mg three times daily for 14 days along with bupropion, a CYP2B6 substrate, reduces the area under the concentration-time curve by approximately 14% and increases the clearance of bupropion by approximately 20% (89662).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B St. John's wort may increase the metabolism and reduce the levels of CYP2C19 substrates.  Details Preliminary clinical research in healthy males shows that taking St. John's wort for 14 days induces CYP2C19 and increases metabolism of mephenytoin (Mesantoin). In patients with wild-type 2C19 (2C19*1/*1) metabolism was almost 4-fold greater in subjects who received St. John's wort compared to placebo. In contrast, patients with 2C19*2/*2 and *2/*3 genotypes did not demonstrate a similar increase in metabolism (17405). Theoretically, St. John's wort might increase metabolism of other CYP2C19 substrates.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B St. John's wort may increase the metabolism and reduce the levels of CYP2C9 substrates.  Details There is contradictory research about the effect of St. John's wort on CYP2C9. Some in vitro research shows that St. John's wort induces CYP2C9, but to a lesser extent than CYP3A4 (9204,10848,11889). St. John's wort also induces metabolism of the S-warfarin isomer, which is a CYP2C9 substrate (11890). Other research shows that St. John's wort 300 mg three times daily for 21 days does not significantly affect the pharmacokinetics of a single 400 mg dose of ibuprofen, which is also a CYP2C9 substrate (15546). Until more is known, use St. John's wort cautiously in patients who are taking CYP2C9 substrates.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B St. John's wort increases the metabolism and reduces the levels of CYP3A4 substrates.  Details St. John's wort induces CYP3A4 enzymes and increases metabolism of CYP3A4 substrates (9204,10830,10847,10848,11889,22423,22424,22425,22427,48603). Clinically significant interactions have been reported with St. John's wort products containing hyperforin 1 mg or more (97171).

DIGOXIN (Lanoxin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort reduces the levels and clinical effects of digoxin.  Details St. John's wort can reduce the bioavailability, serum levels, and therapeutic effects of digoxin. Taking an extract of St. John's wort 900 mg, containing hyperforin 7.5 mg or more, daily for 10-14 days, can reduce serum digoxin levels by 25% in healthy people. St. John's wort is thought to affect the multidrug transporter, P-glycoprotein, which mediates the absorption and elimination of digoxin and other drugs (382,6473,7808,7810,9204,96552,97171). St. John's wort products providing less than 7.5 mg of hyperforin daily do not appear to affect digoxin levels (97171).

DOCETAXEL (Taxotere) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B St. John's wort reduces the levels and clinical effects of docetaxel.  Details Clinical research shows that taking a specific St. John's wort product (Hyperiplant, VSM) 300 mg three times daily for 14 days increases docetaxel clearance by about 14%, resulting in decreased plasma concentrations of docetaxel in cancer patients. This is most likely due to induction of cytochrome P450 3A4 (CYP3A4) by St. John's wort (89661).

FENTANYL Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Theoretically, St. John's wort may reduce the levels and clinical effects of fentanyl.  Details Given that St. John's wort induces cytochrome P450 3A4 (CYP3A4) and P-glycoprotein, it is possible that concomitant use of St. John's wort with fentanyl will reduce plasma levels and analgesic activity of fentanyl (96552). However, some clinical research in healthy adults shows that taking St. John's wort (LI-160, Lichtwer Pharma) 300 mg daily for 21 days does not alter the pharmacokinetics or clinical effects of intravenous fentanyl (102868). It is unclear if these findings can be generalized to oral, intranasal, or transdermal fentanyl.

FEXOFENADINE (Allegra) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B St. John's wort may increase the levels and clinical effects of fexofenadine.  Details A single dose of St. John's wort decreases the clearance of fexofenadine and increases its plasma levels. However, the effect of St. John's wort on plasma levels of fexofenadine seems to be lost if dosing is continued for more than 2 weeks (9685). Patients taking fexofenadine and St. John's wort concurrently should be monitored for possible fexofenadine toxicity.

FINASTERIDE (Proscar, Propecia) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D St. John's wort may reduce the levels and clinical effects of finasteride.  Details St. John's wort reduces plasma levels of finasteride in healthy male volunteers due to induction of finasteride metabolism via cytochrome P450 3A4 (CYP3A4). The clinical significance of this interaction is not known (96552).

GLICLAZIDE (Diamicron, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B St. John's wort may reduce the levels and clinical effects of gliclazide.  Details Taking St. John's wort decreases the half-life and increases clearance of gliclazide in healthy people (22431).

HMG-CoA REDUCTASE INHIBITORS ("Statins") Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B St. John's wort may increase the metabolism and reduce the effectiveness of atorvastatin, lovastatin, and rosuvastatin. However, it does not seem to affect pravastatin, pitavastatin, or fluvastatin.  Details Concomitant use of St. John's wort can reduce plasma concentrations of the active simvastatin metabolite, simvastatin hydroxy acid, by 28%. St. John's wort induces intestinal and hepatic cytochrome P450 3A4 (CYP3A4) and intestinal P-glycoprotein/MDR-1, a drug transporter. This increases simvastatin clearance. It also increases the clearance of atorvastatin (Lipitor), lovastatin (Mevacor), and rosuvastatin (Crestor). St. John's wort does not seem to affect the plasma concentrations of pravastatin (Pravachol), pitavastatin (Livalo) or fluvastatin (Lescol), which are not substrates of CYP3A4 or P-glycoprotein (10627,96552,97171).

IMATINIB (Gleevec) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = A St. John's wort reduces the levels and clinical effects of imatinib.  Details Taking St. John's wort 900 mg daily for 2 weeks reduces the bioavailability and half-life of a single dose of imatinib and decreases its serum levels by 30% in healthy volunteers. This is most likely due to induction of cytochrome P450 3A4 (CYP3A4) by St. John's wort, which increases clearance of imatinib (11888,96552).

INDINAVIR (Crixivan) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D St. John's wort may reduce the levels and clinical effects of indinavir.  Details In healthy volunteers, taking St. John's wort concurrently with indinavir reduces plasma concentrations of indinavir by inducing metabolism via cytochrome P450 3A4 (CYP3A4) (96552). Theoretically, this could result in treatment failure and viral resistance.

IRINOTECAN (Camptosar) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = A St. John's wort reduces the levels and clinical effects of irinotecan.  Details St. John's wort 900 mg daily for 18 days decreases serum levels of irinotecan by at least 50%. Clearance of the active metabolite of irinotecan, SN-38, is also increased, resulting in a 42% decrease in the area under the concentration-time curve (9206,97171). This is thought to be due to induction of cytochrome P450 3A4 (CYP3A4) by St. John's wort (7092,96552).

IVABRADINE (Corlanor) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D St. John's wort might reduce the levels and clinical effects of ivabradine.  Details Taking St. John's wort 900 mg containing 7.5 mg of hyperforin daily for 14 days with a single dose of ivabradine causes a 62% reduction in plasma levels of ivabradine. This interaction is thought to be due to induction of cytochrome P450 3A4 (CYP3A4) by St. John's wort, increasing the metabolism of ivabradine (96552,97171).

KETAMINE (Ketalar) Interaction Rating = Major Do not take this combination. Severity = Moderate •  Occurrence = Likely •  Level of Evidence = B St. John's wort reduces the levels and clinical effects of ketamine.  Details Taking St. John's wort 300 mg three times daily for 14 days can decrease maximum serum levels of ketamine by around 66% and area under the concentration-time curve of ketamine by 58%. This is most likely due to induction of cytochrome P450 3A4 (CYP3A4) by St. John's wort (89663).

MEPHENYTOIN (Mesantoin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort reduces the levels and clinical effects of mephenytoin.  Details Preliminary clinical research in healthy males shows that taking St. John's wort for 14 days induces cytochrome P450 2C19 (CYP2C19) and significantly increases metabolism of mephenytoin (Mesantoin). In people with wild-type 2C19, metabolism was almost 4-fold greater in subjects who received St. John's wort compared to placebo. In contrast, patients with 2C19*2/*2 and *2/*3 genotypes did not demonstrate a similar increase in metabolism (17405).

METHADONE (Dolophine) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B St. John's wort might reduce the levels and clinical effects of methadone.  Details St. John's wort might decrease the effectiveness of methadone by reducing its blood concentrations. In one report, two out of four patients on methadone maintenance therapy for addiction experienced methadone withdrawal symptoms after taking St. John's wort 900 mg daily for a median of 31 days. There was a median decrease in blood methadone concentration of 47% (range: 19% to 60%) when compared to baseline (22419).

METHYLPHENIDATE (Concerta, others) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D St. John's wort might reduce the levels and clinical effects of methylphenidate.  Details St. John's wort might decrease the effectiveness of methylphenidate. In one report, an adult male, stabilized on methylphenidate for attention deficit-hyperactivity disorder (ADHD), experienced increased attention problems and ADHD symptoms after taking St. John's wort 600 mg daily for 4 months. ADHD symptoms improved when St. John's wort was discontinued (15544). The mechanism of this interaction is unknown.

NON-NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITORS (NNRTIs) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of NNRTIs.  Details St. John's wort increases the oral clearance of nevirapine (Viramune) by 35%. Subtherapeutic concentrations are associated with therapeutic failure, development of viral resistance, and development of drug class resistance. St. John's wort induces intestinal and hepatic cytochrome P450 3A4 (CYP3A4) and intestinal P-glycoprotein/MDR-1, a drug transporter (1290,1340,4837,96552).

OMEPRAZOLE (Prilosec) Interaction Rating = Major Do not take this combination. Severity = Moderate •  Occurrence = Likely •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of omeprazole.  Details Taking St. John's wort, 300 mg orally three times daily for 14 days, reduces serum concentrations of omeprazole by inducing its metabolism via cytochrome P450 (CYP) 2C19 and 3A4. The reduction of omeprazole serum levels is dependent on CYP2C19 genotype, with reductions up to 50% in extensive metabolizers and 38% in poor metabolizers (22440,96552).

OXYCODONE (Oxycontin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of oxycodone.  Details St. John's wort can increase oxycodone metabolism by inducing cytochrome P450 3A4 (CYP3A4), reducing plasma levels and analgesic activity (96552).

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of P-glycoprotein substrates.  Details St. John's wort induces P-glycoprotein. P-glycoprotein is a carrier mechanism responsible for transporting drugs and other substances across cell membranes. When P-glycoprotein is induced in the gastrointestinal (GI) tract, it can prevent the absorption of some medications. In addition, induction of p-glycoprotein can decrease entry of drugs into the central nervous system (CNS) and decrease access to other sites of action (382,1340,7810,11722).

PHENOBARBITAL (Luminal) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of phenobarbital.  Details St. John's wort may increase the metabolism of phenobarbital. Plasma concentrations of phenobarbital should be monitored carefully. The dose of phenobarbital may need to be increased when St. John's wort is started and decreased when it is stopped (9204).

PHENPROCOUMON (Marcoumar, others) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of phenprocoumon.  Details St. John's wort appears to increase the metabolism of phenprocoumon (an anticoagulant that is not available in the US) by increasing the activity of the cytochrome P450 2C9 (CYP2C9) enzyme. This may result in decreases in the anticoagulant effect and international normalized ratio (INR) (9204).

PHENYTOIN (Dilantin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of phenytoin.  Details St. John's wort may increase the metabolism of phenytoin. Plasma concentrations of phenytoin should be monitored closely. The dose of phenytoin may need to be increased when St. John's wort is started and decreased when it is stopped (9204).

PHOTOSENSITIZING DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, St. John's wort might increase the likelihood for photosensitivity reactions when used in combination with photosensitizing drugs.  Details St. John's wort might increase photosensitivity reactions due to its hypericin content (166). However, some clinical research shows that very high doses of St. John's wort are needed to produce phototoxicity in humans (3900,4542,76266).

PROCAINAMIDE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, St. John's wort might decrease the levels and clinical effects of procainamide.  Details Animal research shows that taking St. John's wort extract increases the bioavailability of procainamide, but does not increase its metabolism (14865). Whether this interaction is clinically significant in humans is not known.

PROTEASE INHIBITORS (PIs) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort reduces the levels and clinical effects of PIs.  Details In healthy volunteers, St. John's wort can reduce the plasma concentrations of indinavir (Crixivan) by inducing cytochrome P450 3A4 (CYP3A4). This might result in treatment failure and viral resistance (1290,7808,96552). St. John's wort also induces P-glycoprotein, which can result in decreased intracellular protease inhibitor concentrations and increased elimination (9204).

RESERPINE (Raudixin, others) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, St. John's wort might decrease the effectiveness of reserpine.  Details Animal research shows that St. John's wort can antagonize the effects of reserpine (758).

RIVAROXABAN (Xarelto) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of rivaroxaban.  Details A small pharmacokinetic study in healthy volunteers shows that taking a single dose of rivaroxaban 20 mg after using a specific St. John's wort extract (Jarsin, Vifor SA) 450 mg orally twice daily for 14 days reduces the bioavailability of rivaroxaban by 24% and reduces rivaroxaban's therapeutic inhibition of factor Xa by 20% (104038).

SEROTONERGIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, St. John's wort might inhibit reuptake and increase levels of serotonin, resulting in additive effects with serotonergic drugs.  Details Concomitant use of serotonergic drugs with St. John's wort can lead to increased adverse effects and increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstriction disorders (166,542,3569,8056,110318).

TACROLIMUS (Prograf) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of tacrolimus.  Details Taking a St. John's wort extract (Jarsin) 600 mg daily significantly decreases tacrolimus serum levels. Dose increases of 60% may be required to maintain therapeutic tacrolimus levels in patients taking St. John's wort. St. John's wort is thought to lower tacrolimus levels by inducing cytochrome P450 3A4 (CYP3A4) enzymes (7095,10329).

THEOPHYLLINE Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Unlikely •  Level of Evidence = D St. John's wort might decrease the levels of theophylline, although this effect might not be clinically relevant.  Details St. John's wort does not seem to significantly affect theophylline pharmacokinetics (11802). There is a single case report of a possible interaction with theophylline. A patient who smoked and was taking 11 other drugs experienced an increase in theophylline levels after discontinuation of St. John's wort. This increase has been attributed to a rebounding of theophylline serum levels after St. John's wort was no longer present to induce metabolism via cytochrome P450 1A2 (CYP1A2) (3556,7808,9204). However, studies in healthy volunteers show that St. John's wort is unlikely to affect theophylline to any clinically significant degree (11802).

TRAMADOL (Ultram) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D St. John's wort might decrease the levels and clinical effects of tramadol.  Details St. John's wort can increase tramadol metabolism via induction of cytochrome P450 3A4 (CYP3A4), reducing plasma levels and analgesic activity (96552). Theoretically, concurrent use of St. John's wort with tramadol might also cause additive serotonergic effects (763,6427,8056,8936).

VORICONAZOLE (Vfend) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B St. John's wort might decrease the levels and clinical effects of voriconazole.  Details Clinical research shows that taking St. John's wort with voriconazole reduces voriconazole exposure and increases voriconazole metabolism by approximately 107%. Voriconazole is primarily metabolized by cytochrome P450 (CYP) 2C19, with CYP3A4 and CYP2C9 also involved (89660). St. John's wort induces CYP2C19, CYP3A4, and CYP2C9 (9204,10830,10847,10848,11889,11890,17405,22423,22424,22425)(22427,48603).

WARFARIN (Coumadin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Likely •  Level of Evidence = B St. John's wort decreases the levels and clinical effects of warfarin.  Details Taking St. John's wort significantly increases clearance of warfarin, including both its R- and S-isomers (11890,15176). This is likely due to induction of cytochrome P450 (CYP) 1A2 and CYP3A4 (11890). St. John's wort can also significantly decrease International Normalized Ratio (INR) in people taking warfarin (1292). In addition, taking warfarin at the same time as St. John's wort might reduce warfarin bioavailability. When a dried extract is mixed with warfarin in an aqueous medium, up to 30% of warfarin is bound to particles, reducing its absorption (10448).

ZOLPIDEM (Ambien) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B St. John's wort might decrease the levels and clinical effects of zolpidem.  Details In clinical research, concomitant use of zolpidem with St. John's wort decreased zolpidem plasma levels due to induction of its metabolism by cytochrome P450 3A4 (22441,96552). Whether this interaction is clinically significant is not known.

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General ...Orally, boneset is reported to cause nausea and severe diarrhea and vomiting (12842). Additionally, other plants in the Eupatorium genus contain the hepatotoxic pyrrolizidine alkaloids (PAs). However, the alkaloids in boneset have not been adequately characterized to determine their toxic potential (12842,102557). Liver toxicity and liver damage may be possible in high doses.

Gastrointestinal ...Orally, boneset has been reported to cause nausea and severe diarrhea and vomiting (12842).

Hepatic ...Other plants in the Eupatorium genus contain hepatotoxic pyrrolizidine alkaloids (PAs). However, the alkaloids in boneset have not been adequately characterized to determine their toxic potential (12842,102557). Liver toxicity and liver damage may be possible in high doses.

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General ...Orally, echinacea is well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, constipation, diarrhea, heartburn, nausea and vomiting, rashes, and stomach upset.
Serious Adverse Effects (Rare):
Orally: Severe allergic reactions and hepatitis have been reported.

Dermatologic ...Itching, urticaria, tingling, and allergic rashes have been reported with various echinacea preparations (8225,12355,17519,20059,20077,101592,111530,111540). In a study of children aged 2-11 years, rash occurred in about 7% of children treated with an extract of the above-ground parts of E. purpurea (EC31J2, Echinacin Saft, Madaus AG), compared with about 3% of those treated with placebo (4989,95652). There is concern that allergic reactions could be severe in some children. The Medicines and Healthcare Products Regulatory Agency in the United Kingdom (UK) recommends against the use of oral echinacea products in children under 12 years of age due to this risk of allergic reaction (18207). However, another study in children 4-12 years old shows that a specific E. purpurea product (Echinaforce Junior, A. Vogel) did not cause allergic or urticarial reactions more frequently than vitamin C (105719).

Gastrointestinal ...Gastrointestinal adverse effects include nausea and vomiting, abdominal pain, stomach upset, heartburn, diarrhea, and constipation (10802,11970,12355,13419,17519,20059,48680,105719,106626). An unpleasant taste, dry mouth, and burning, tingling or numbness of the tongue also occur (11970,12355,17519,20059,20070,20077).

Hematologic ...A 51-year-old female presented with leukopenia after taking echinacea 450 mg three times daily for 2 months, along with ginkgo biloba, multivitamins, and calcium. Her leukocyte count recovered upon stopping these supplements, but dropped again when she restarted echinacea alone about a year later. The problem resolved when echinacea was stopped permanently (48533). A 32-year-old male presented with severe thrombotic thrombocytopenic purpura (TTP) about 2 weeks after using an extract of E. pallida to treat a cold. He required admission to an intensive care unit and extensive plasmapheresis. The authors speculate that immunostimulant effects of echinacea induced or exacerbated the TTP (48572).

Hepatic ...Although uncommon, cases of echinacea-induced hepatitis have been reported. One case report describes acute cholestatic autoimmune hepatitis in a 45-year-old male who had been taking an echinacea root extract 1500 mg daily for about 2 weeks. He presented with significantly elevated liver function tests (LFTs), elevated immunoglobulin G (IgG) levels, and a positive test for anti-smooth muscle antibodies, indicating an autoimmune process. Elevated LFTs and IgG levels returned to normal within one month of stopping echinacea (17518). Another case report describes acute cholestatic hepatitis in a 44-year-old male who had taken echinacea root tablets 600 mg daily for 5 days to treat flu-like symptoms. He presented with elevated LFTs, prothrombin time, and international normalized ratio (INR). His condition gradually improved after stopping echinacea, and his LFTs normalized within 3 months (91528).
Seven cases of hepatitis associated with echinacea use were reported to the Australian Adverse Drug Reactions Advisory Committee between 1979 and 2000, but specific details are lacking (8225).
One case report describes acute liver failure in a 2 year-old child who had been given about 100 mg of echinacea daily for 2 weeks. The patient presented with jaundice, diarrhea, lethargy, anorexia, and significantly elevated LFTs. A liver biopsy showed hepatocyte swelling, spotty necrosis, and inflammatory infiltrate with eosinophils. A full recovery was made over a 2-week period (88166).

Immunologic ...Allergic reactions, including urticaria, runny nose, dyspnea, bronchospasm, acute asthma, angioedema, and anaphylaxis, have been reported with various echinacea preparations (638,1358,8225). Atopic individuals and those sensitive to other members of the Asteraceae family (ragweed, chrysanthemums, marigolds, daisies) seem to be at higher risk for these reactions (1358,8225).
A case report describes a 36-year-old female who presented with muscle weakness, electrolyte abnormalities, renal tubular acidosis, fatigue, and dry mouth and eyes after taking echinacea, kava, and St. John's Wort for 2 weeks., She also had a positive antinuclear antibody (ANA) test, with elevated anti-dsDNA antibodies SSA and SSB. Sjogren syndrome was diagnosed; the authors hypothesize that it may have been triggered by the immunostimulant effects of echinacea (10319). A 55-year-old male with a history of pemphigus vulgaris in remission for about a year experienced a flare of the disease after taking an echinacea supplement for one week. After stopping echinacea, medical treatment resulted in partial control of the disease (12171). Another case report describes a 58-year-old male who presented with marked eosinophilia and elevated immunoglobulin E (IgE) levels while taking an echinacea supplement. He required prednisone therapy until he stopped taking echinacea 3 years later, at which time his eosinophils and IgE normalized (48623). A 41-year-old male experienced four episodes of erythema nodosum, each occurring after he had taken echinacea for early symptoms of influenza. After stopping echinacea, he had no further exacerbations of erythema nodosum, suggesting that it had been triggered by the immunostimulant effects of echinacea (7057).

Musculoskeletal ...Reports of arthralgia and myalgia have been associated with echinacea (13418).

Neurologic/CNS ...Headache has been reported in people taking various echinacea preparations orally (3282,11970,17519,20059,20064). Dizziness has also been reported (3282,8225,11970). In one study using an alcoholic extract of the above-ground parts of E. purpurea (EC31J0, Echinacin, Madaus AG), somnolence and a tendency to aggressiveness were reported (3282).

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General ...There is limited reliable information available about the safety of goldenseal when used in more than a single dose. Berberine, a constituent of goldenseal, is generally well tolerated when used orally.
Most Common Adverse Effects:
Orally: Berberine, a constituent of goldenseal, can cause abdominal distension, abdominal pain, bitter taste, constipation, diarrhea, flatulence, headache, nausea, and vomiting.

Dermatologic ...Orally, berberine, a constituent of goldenseal, may cause rash. However, this appears to be rare (34285). A case of photosensitivity characterized by pruritic, erythematous rash on sun-exposed skin has been reported in a 32-year-old female taking a combination product containing goldenseal, ginseng, bee pollen, and other ingredients. The rash resolved following discontinuation of the supplement and treatment with corticosteroids (33954). It is not clear if this adverse effect is due to goldenseal, other ingredients, or the combination.

Endocrine ...A case of severe, reversible hypernatremia has been reported in an 11-year-old female with new-onset type 1 diabetes and diabetic ketoacidosis who took a goldenseal supplement (52592).

Gastrointestinal ...Orally, berberine, a constituent of goldenseal, may cause diarrhea, constipation, flatulence, vomiting, abdominal pain, abdominal distention, and bitter taste (33648,33689,34245,34247,34285,91953). Theoretically, these effects may occur in patients taking goldenseal. However, this hasn't been reported in clinical research or case reports.

Neurologic/CNS ...Orally, berberine, a constituent of goldenseal, may cause headache when taken in a dose of 5 mg/kg daily (33648). Theoretically, this may occur with goldenseal, but this hasn't been reported in clinical research or case reports.

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General ...Orally, St. John's wort is generally well tolerated.
Most Common Adverse Effects:
Orally: Diarrhea, dizziness, dry mouth, gastrointestinal discomfort (mild), fatigue, headache, insomnia, restlessness, and sedation.
Topically: Skin rash and photodermatitis.
Serious Adverse Effects (Rare):
Orally: There have been rare case reports of suicidal ideation and psychosis after taking St. John's wort.

Cardiovascular ...In clinical research, palpitations have been reported for patients taking St. John's wort orally, although the number of these events was higher for the patients taking sertraline (76070). In one case report, an adult female developed recurrent palpitations and supraventricular tachycardia (SVT) within 3 weeks of initiating St. John's wort 300 mg daily. SVT and related symptoms responded to Valsalva maneuvers and did not recur after discontinuing therapy (106051).
Edema has also been reported in clinical research for some patients treated with St. John's wort 900-1500 mg daily for 8 weeks (10843). Cardiovascular collapse following induction of anesthesia has been reported in an otherwise healthy patient who had been taking St. John's wort for 6 months (8931). A case of St. John's wort-induced hypertension has been reported for a 56-year-old patient who used St. John's wort extract 250 mg twice daily for 5 weeks. Blood pressure normalized after discontinuation of treatment (76073). A case of new-onset orthostatic hypotension and light-headedness has been reported for a 70 year-old homebound patient who was taking multiple prescription medications and herbal products, including St. John's wort (76128). When all herbal products were discontinued, these symptoms improved, and the patient experienced improvement in pain control.

Dermatologic ...Both topical and chronic oral use of St. John's wort can cause photodermatitis (206,620,758,4628,4631,6477,13156,17986,76072,76148)(95506,110318). The average threshold dose range for an increased risk of photosensitivity appears to be 1.8-4 grams St. John's wort extract or 5-10 mg hypericin, daily. Lower doses might not cause this effect (4542,7808). For example, a single dose of St. John's wort extract 1800 mg (5.4 mg hypericin) followed by 900 mg (2.7 mg hypericin) daily does not seem to produce skin hypericin concentrations thought to be high enough to cause phototoxicity (3900,4542,76266). Females appear to have a higher risk of dose-related photosensitivity. In a dose-ranging, small clinical trial, almost all of the female participants experienced mild to moderate photosensitivity with paresthesia in sun-exposed skin areas after administration of St. John's wort (Jarsin, Casella Med) 1800 mg daily for 3-6 days. Symptoms resolved about 12-16 days after discontinuation (95506). Male participants reported no adverse effects at this dose, and both genders reported no adverse effects at lower doses. Light or fair-skinned people should employ protective measures against direct sunlight when using St. John's wort either topically or orally (628).
Total body erythroderma without exposure to sunlight, accompanied by burning sensation of the skin, has also been reported (8930). Orally, St. John's wort may cause pruritus or skin rash, although these events seem to occur infrequently (76140,76148,76245). A case of persistent scalp and eyebrow hair loss has been reported for a 24-year-old schizophrenic female who was taking olanzapine plus St. John's wort 900 mg/day orally (7811). Also, a case of surgical site irritation has been reported for a patient who applied ointment containing St. John's wort (17225).

Endocrine ...A case of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in a 67-year-old male with depression has been reported. During a 3-month period, the patient was taking St. John's wort 300 mg daily then increased to 600-900 mg daily with no adverse effects despite a low serum sodium level of 122mEq/L, elevated levels of urine sodium, and urine osmolality suggestive of SIADH. St. John's wort appeared to be the only contributing factor. The patient's sodium level normalized 3 weeks after discontinuation of St. John's wort (95508).

Gastrointestinal ...Orally, St. John's wort may cause dyspepsia, anorexia, diarrhea, nausea, vomiting, and constipation, although these events seems to occur infrequently (4897,13021,17986,76070,76071,76113,76146,76150,76271).

Genitourinary ...Orally, St. John's wort can cause intermenstrual or abnormal menstrual bleeding (1292,76056). However, this effect has occurred in patients who were also taking an oral contraceptive. Changes in menstrual bleeding might be the result of a drug interaction (1292,76056). Also, St. John's wort has been associated with anorgasmia and frequent urination when used orally (10843,76070).
Sexual dysfunction can occur with St. John's wort, but less frequently than with SSRIs (10843). A case of erectile dysfunction and orgasmic delay has been reported for a 49-year-old male after taking St. John's wort orally for one week. Co-administration of sildenafil 25-50 mg prior to sexual activity reversed the sexual dysfunction. Previously, the patient had experienced orgasmic delay, erectile dysfunction, and inhibited sexual desire when taking a selective serotonin reuptake inhibitor (sertraline) (4836).

Hepatic ...A case of acute hepatitis with prolonged cholestasis and features of vanishing bile duct syndrome has been reported for a patient who used tibolone and St. John's wort orally for 10 weeks (76135). A case of jaundice with transaminitis and hyperbilirubinemia has been reported for a 79 year-old female who used St. John's wort and copaiba (95505). Laboratory values normalized 7 weeks after discontinuation of both products.

Musculoskeletal ...Orally, St. John's wort may cause muscle or joint stiffness, tremor, muscle spasms, or pain, although these events appear to occur rarely (76070).

Neurologic/CNS ...St. John's wort may cause headache, dizziness, fatigue, lethargy, or insomnia (5096,13021,76070,76071,76113,76132,76133,76150,89666). Isolated cases of paresthesia have been reported for patients taking St. John's wort (5073). A case of subacute toxic neuropathy has been reported for a 35-year-old female who took St. John's wort 500 mg daily orally for 4 weeks (621).

Ocular/Otic ...There is concern that taking St. John's wort might increase the risk of cataracts. The hypericin constituent of St. John's wort is photoactive and, in the presence of light, may damage lens proteins, leading to cataracts (1296,17088). In population research, people with cataracts were significantly more likely to have used St. John's wort compared to people without cataracts (17088). Ear and labyrinth disorders have been possibly attributed to use of St. John's wort in clinical research, although these events rarely occur (76120).

Psychiatric ...St. John's wort can induce hypomania in depressed patients and mania in depressed patients with occult bipolar disorder (325,3524,3555,3568,10845,76047,76064,76137,110318). Cases of first-episode psychosis have been reported for females who used St. John's wort orally. In both cases, symptoms resolved following discontinuation of St. John's wort and treatment with antipsychotics for several weeks (13015,89664). Also, psychosis and delirium have been reported for a 76-year-old female patient who used St. John's wort for 3 weeks. The patient may have been predisposed to this effect due to undiagnosed dementia (76270). Restlessness, insomnia, panic, and anxiety have been noted for some patients taking St. John's wort orally (5073,13156,76070,76132,76268,76269,89665).
In isolated cases, St. John's wort has been associated with a syndrome consisting of extreme anxiety, confusion, nausea, hypertension, and tachycardia. These symptoms may occur within 2-3 weeks after it is started, in patients with no other predisposing factors. This syndrome has been diagnosed as the serotonin syndrome (6201,7811,110318). In one case, the symptoms began after consuming tyramine-containing foods, including aged cheese and red wine (7812). In an isolated case, a 51-year-old female reported having had suicidal and homicidal thoughts for 9 months while taking vitamin C and a St. John's wort extract. Symptoms disappeared within 3 weeks of discontinuing treatment (76111). A case of decreased libido has been reported for a 42-year-old male with mood and anxiety disorders who had taken St. John's wort orally for 9 months (7312).
St. John's wort has been associated with withdrawal effects similar to those found with conventional antidepressants. Headache, nausea, anorexia, dry mouth, thirst, cold chills, weight loss, dizziness, insomnia, paresthesia, confusion, and fatigue have been reported. Withdrawal effects are most likely to occur within two days after discontinuation but can occur one week or more after stopping treatment in some people. Occurrence of withdrawal symptoms may not be related to dose or duration of use (3569,11801).

Pulmonary/Respiratory ...Orally, St. John's wort may cause sore throat, swollen glands, laryngitis, sinus ache, sweating, and hot flashes, although the frequency of these events appears to be similar to placebo (76150).

Renal ...Orally, St. John's wort has been associated with a case report of acute kidney failure in a 46-year-old female after one dose of homemade St. John's wort tea. Three sessions of hemodialysis were required before there was full recovery (106741). However, causality is unclear since the patient had also been taking diclofenac intermittently for a month prior to developing kidney failure.

Other ...Sjogren's syndrome has been reported in a patient taking herbal supplements including St. John's wort, echinacea, and kava. Echinacea may have been the primary cause, because Sjogren's syndrome is an autoimmune disorder. The role of St. John's wort in causing this syndrome is unclear (10319).

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