Herbal Laxative [Discontinued] by Thorne Research

POSSIBLY EFFECTIVE

• Constipation. Alder buckthorn contains laxative anthraquinones, which are known to relieve constipation (3,4,7,12). Alder buckthorn has laxative effects comparable to cascara (3). There is insufficient reliable information available about the effectiveness of alder buckthorn for its other uses.

(Read more about ALDER BUCKTHORN)

There is insufficient reliable information available about the effectiveness of blue flag.

(Read more about BLUE FLAG)

POSSIBLY INEFFECTIVE

• Bowel preparation. Taking cascara sagrada orally with magnesium sulfate or magnesium hydroxide prior to colonoscopy does not appear to improve bowel cleansing when used alone or as an adjunct to polyethylene glycol. Details: Some clinical research shows that taking a specific combination of cascara sagrada plus magnesium sulfate (Pico-Salax) orally along with polyethylene glycol (GoLYTELY) is not more effective than polyethylene glycol alone for bowel preparation prior to colonoscopy (40086). Other clinical research shows that taking cascara sagrada plus magnesium sulfate orally, alone or in combination with polyethylene glycol (GoLYTELY), is actually less effective than polyethylene glycol alone (40087,40088). Additionally, some clinical research shows that taking a combination of cascara sagrada 5 mL plus milk of magnesia 30 mL orally does not improve bowel cleansing or examination quality when compared with no bowel preparation (40090,40093).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Constipation. It is unclear if oral cascara sagrada is beneficial in patients with constipation. Details: Cascara sagrada has a history of use for its laxative effects in patients with constipation (272). In fact, cascara sagrada was formerly approved by the US Food and Drug Administration (FDA) as a safe and effective over-the-counter (OTC) laxative; however, this designation was removed in 2002 due to a lack of supporting evidence (8229). More evidence is needed to rate cascara sagrada for this use.

(Read more about CASCARA SAGRADA)

POSSIBLY EFFECTIVE

• Menopausal symptoms. Oral rhubarb root extract seems to help improve symptoms of menopause. Details: Clinical research in perimenopausal and postmenopausal patients shows that taking a specific dry extract of rhubarb root (ERr 731, Estroease, Lupin Pharmaceuticals) 4 mg orally daily for 3-27 months improves symptoms of menopause by 46% to 83% compared to an improvement of less than 20% with placebo. About 83% of females taking the rhubarb extract report overall clinical improvement, with specific improvements in anxiety, hot flushes, sweating, sleep, mood, quality of life, fatigue, sexual problems, urinary tract problems, vaginal dryness, and joint and muscle issues (92294,92295,92296,92297,92298,108960).
• Pancreatitis. Oral or rectal rhubarb might improve symptoms and duration of hospital stay in individuals with acute pancreatitis. It is unclear if oral rhubarb helps to prevent pancreatitis in individuals undergoing endoscopic retrograde cholangiopancreatography (ERCP). Details: Meta-analyses of clinical research in adults with acute pancreatitis in China shows that administering rhubarb 10-90 grams daily via gastric tube or rectal enema for 3-14 days, in combination with somatostatin, octreotide, or ulinastatin, reduces the risk for complications such as sepsis or kidney failure by 45%, duration of abdominal pain by 1.3-2 days, and duration of hospital stay by 6.7-6.9 days when compared with taking these medications alone (97922,100964). However, the included studies were of low methodological quality. Additionally, somatostatin and octreotide are not recommended for the treatment of acute pancreatitis by the American College of Gastroenterology or the American Gastroenterological Association (101001,100965). A separate meta-analysis and individual clinical studies show that administering rhubarb 6-20 grams 1-3 times daily for 5-14 days, usually via nasojejunal tube with early enteral nutrition, reduces the duration of hospital stay and improves abdominal symptoms when compared with enteral nutrition alone (92301,103475). The meta-analysis shows that administering rhubarb reduces hospital stay by 4.5 days and intensive care unit stay by 2.8 days. The use of rhubarb also reduced the duration of severe abdominal pain, abdominal distention, and abnormal bowel sounds by 1-2 days. However, there was no effect on mortality rate, infection rate, or the incidence of multiple organ dysfunction (103475). Rhubarb has also been studied for the prevention of pancreatitis in patients undergoing a specific procedure called endoscopic retrograde cholangiopancreatography (ERCP). Preliminary clinical research in patients at high risk for post-ERCP complications shows that drinking a raw rhubarb solution after the procedure reduces the incidence of post-ERCP pancreatitis by 74% and post-ERCP hyperamylasemia by 81% when compared to standard care. However, this study was of low methodological quality, and the rhubarb solution preparation and dose were not reported (97920).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acute respiratory distress syndrome (ARDS). It is unclear if oral rhubarb reduces ARDS. Details: A small clinical study in patients with ARDS shows that administering rhubarb leachate 10 grams in 30 mL water via nasogastric tube three times daily for 7 days, in addition to standard treatment, modestly improves oxygenation and reduces indices of pulmonary vascular permeability when compared with standard treatment (97921).
• Appendicitis. Oral rhubarb has only been evaluated in combination with other ingredients for use in pediatric appendiceal abscess; its effect when used alone is unclear. Details: A large observational study in children 3-14 years old with appendiceal abscess also receiving intravenous antibiotics suggests that taking a rhubarb peony decoction twice daily for 7-14 days is associated with a higher clinical cure rate of 93% when compared with 81% in the control group, but does not improve length of stay, post-operative complications, or recurrence rate (112380). However, it is unclear if the effects are from rhubarb, other ingredients, or the combination.
• Canker sores. Topical rhubarb has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small open-label clinical study in adults with mild canker sores shows that topical application of a specific combination product (Pyralvex Soluté, Laboratoires Norgine Pharma) containing rhubarb extract 5% and salicylic acid reduces the time to symptom resolution by about 3 days when compared to using a water control (97919).
• Chronic kidney disease (CKD). It is unclear if oral rhubarb prevents the progression of CKD or improves markers of kidney function. Details: A meta-analysis of results from two low-quality clinical studies shows that taking rhubarb 1-7.7 grams daily for up to 48 months as part of traditional Chinese medicine does not delay the onset of kidney failure when compared with standard treatment (92302). However, these results were calculated using regression analysis rather than long-term follow-up, which limits the validity of these findings. Another meta-analysis of clinical research shows that rhubarb may improve serum creatinine and blood urea nitrogen in patients with CKD when compared with no treatment (92302). However, rhubarb does not appear to improve blood urea nitrogen when compared with captopril (71329). The validity of the research to date is limited by the low to very low methodological quality of the studies and the high risk of bias. Additionally, all of the studies were conducted in China; it is unclear if these findings are applicable to other populations.
• Constipation. It is unclear if rhubarb is beneficial for constipation. Details: A small clinical study in middle-aged adults with constipation shows that taking rhubarb extract 12.5 mg or 25 mg based on rhein content (Gutisrheum, Laboratories Ortis) at bedtime for 1 month improves stool frequency and consistency when compared with placebo (112381). The validity of these findings is limited by patient-reported outcomes. A clinical study in patients with chronic constipation, defined as having a bowel movement no more than twice per week, shows that a specific combination product (Nucarb; Wilshire Laboratories Ltd) containing rhubarb extract 250 mg, activated charcoal 180 mg, calcium sennosides 50 mg, peppermint oil 0.5 mg, fennel oil 0.5 mg, and sulfur 50 mg, taken as two tablets at bedtime for one week, followed by 1 tablet at bedtime for 1 week, reduces passing gas, abdominal pain, and sensation of bloating by 81%, 73%, and 72% respectively, when compared with baseline. Sensation of straining, severity of constipation, and feeling of incomplete evacuation were reduced by 69%, 67%, and 54% respectively, when compared with baseline (108853). The validity of these findings is limited by the lack of a comparator group, and it is unclear whether the effects are due to rhubarb, the combination, or other ingredients.
• Dysmenorrhea. It is unclear if oral rhubarb reduces dysmenorrhea. Details: Preliminary clinical research in young adults with dysmenorrhea shows that taking rhubarb root and rhizome powder 2520 mg daily, beginning 2 days before menstruation and continuing for 5 days, repeated for three consecutive cycles, has similar efficacy to mefenamic acid 500 mg three times daily in reducing pain and improving quality of life. Those receiving either treatment experienced an overall improvement of greater than 80%, which is attributed to a reduction in pain, fatigue, headache, and gastrointestinal symptoms (92300).
• Gastrointestinal bleeding. It is unclear if spraying rhubarb powder with a gastroscope reduces gastrointestinal bleeding. Details: In patients with acute gastrointestinal bleeding, a meta-analysis of mainly preliminary clinical research shows that spraying rhubarb powder under a gastroscope has a small to moderate hemostatic effect over 24-72 hours when compared with norepinephrine. The risk of re-bleeding over 48 hours was also reduced by about 58% (103474).
• Herpes labialis (cold sores). Topical rhubarb has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that applying a cream containing rhubarb and sage to cold sores is similarly effective to acyclovir (Zovirax) cream. Acyclovir cream heals lesions in about 6.3 days; the rhubarb and sage cream heals lesions in about 7.2 days (10437). It is not clear if these improvements are due to the treatments used or to the natural resolution of the cold sores. Additionally, it is unclear if the benefit is due to rhubarb, other ingredients, or the combination.
• Hypercholesterolemia. It is unclear if oral rhubarb helps to lower cholesterol levels. Details: A very small clinical study including 10 males with hypercholesterolemia shows that eating ground rhubarb stalk fiber 27 grams daily for 4 weeks reduces total cholesterol by 8% and low-density lipoprotein (LDL) cholesterol by 9%, but does not affect high-density lipoprotein (HDL) cholesterol levels, when compared to baseline (71363). The validity of these findings is limited by the very small study size and the lack of a comparator group.
• Malignant pleural effusions. Topical rhubarb powder has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients living in China with advanced malignant cancer and malignant pleural effusions shows that applying a combination product (Hehuang Company) containing rhubarb powder 100 grams and mirabilite 400 grams to the chest wall for 8 hours daily for 28 days as an adjunct to standard therapy leads to partial or complete reduction of effusion in 67% of participants, compared with 55% of those receiving placebo and standard therapy (105961).
• Nasopharyngeal cancer. Oral rhubarb has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with nasopharyngeal carcinoma shows that taking a specific combination product (Shenlong) containing rhubarb and other herbs along with radiation therapy does not improve tumor remission or survival when compared to radiation therapy alone (71380).
• Nonalcoholic fatty liver disease (NAFLD). Oral rhubarb has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with NAFLD shows that taking 3-5 tablets of a specific Chinese herbal medicine (Danning Pian) containing rhubarb, giant knotweed, dried green orange peel, and dried ripe orange peel three times daily for 3 month improves lipids, liver function, and clinical symptoms (71315). It is not clear if this effect is due to rhubarb, the other ingredients, or the combination.
• Obesity. It is unclear if oral rhubarb is beneficial for weight loss. Details: A small clinical study in overweight and obese females shows that taking rhubarb with ginger, astragalus, red sage, and turmeric does not reduce body weight when compared with placebo (20346).
• Organophosphorus pesticide poisoning. It is unclear if giving rhubarb by gastric tube, nasal feeding, or enema is beneficial for organophosphorus pesticide poisoning. Details: A meta-analysis of low-quality clinical research in patients with acute organophosphorus pesticide poisoning shows that taking crude rhubarb 9-120 grams daily via gastric tube, nasal feeding, or retention enema, in conjunction with standard treatment, decreases the incidence of intermediate syndrome by 78% and organ dysfunction syndrome by 66% when compared to standard treatment alone. Rhubarb also reduces the duration of hospital stay by 2.8 days, but with no change in mortality rate, when compared to standard treatment alone. Standard treatment in these studies included atropine, pralidoxime, ventilation, diuresis, other supportive measures, and/or mannitol (92303).
• Sepsis. It is unclear if oral rhubarb is beneficial for sepsis. Details: A meta-analysis of low-quality clinical research in patients with sepsis or systemic inflammatory response syndrome (SIRS) shows that taking rhubarb powder in conjunction with conventional therapy reduces the incidence of gastrointestinal dysfunction, but does not reduce mortality rate, when compared to conventional therapy alone (92305).
• Stroke. Oral rhubarb has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of clinical research in patients with acute ischemic stroke shows that taking traditional Chinese medicine containing rhubarb root and rhizome in conjunction with traditional Western medicine for up to 30 days enhances overall clinical improvement by 27% when compared with traditional Western medicine alone. However, the validity of this outcome is limited by small sample size, the variability in the Chinese medicine formulas used, and the high risk for bias of the included studies (92299). More evidence is needed to rate rhubarb for these uses.

(Read more about RHUBARB)

LIKELY EFFECTIVE

• Constipation. Taking senna orally is effective for the short-term treatment of constipation. Details: Senna is an FDA-approved nonprescription drug marketed for the short-term treatment of constipation in adults and children ages 2 years and older (15429,15433,15436,15441,15442,74545,74607,74609,74613,74615). Senna usually produces a laxative effect 6-10 hours after oral administration (15429,96559). However, in children ages 3-15 years, mineral oil and lactulose might be more effective (15434,15435). Taking senna with psyllium is also effective for the short-term treatment of constipation (8424,74593), with the combination increasing stool moisture to a greater degree than psyllium alone (8424). In patients with opioid or loperamide-induced constipation, taking senna appears to be as effective as lactulose, psyllium, and docusate for relieving constipation (15432,74586,74644,74650). Some population research has found that senna may be more effective than docusate, polyethylene glycol, and lactulose for preventing problematic constipation, the need for an enema, and abdominal imaging in pediatric cancer patients receiving opioids (92710). Senna also seems to be beneficial in chronic constipation. Clinical guidelines published by the American Gastroenterology Association and American College of Gastroenterology in 2023 give a conditional recommendation suggesting the use of senna over managing chronic idiopathic constipation without senna based on low-quality of evidence conducted over 4 weeks (112859). In geriatric patients, senna plus psyllium is more effective than lactulose for treating chronic constipation (15438,15439,15440). Also, a small study in middle-aged adults with chronic idiopathic constipation shows that taking senna (ALOSENN granules) 500 mg twice daily for 4 weeks seems to be similarly effective to taking magnesium oxide 500 mg three times daily (105959).

POSSIBLY EFFECTIVE

• Bowel preparation. Taking oral senna might be effective for bowel cleansing before colonoscopy. Details: A meta-analysis of 10 clinical trials in adults shows that taking senna alone or with other bowel preparations does not improve bowel cleansing before elective colonoscopy when compared with non-senna bowel preparations. However, in a subgroup analysis of 3 clinical studies, taking senna solution alone is about 2.5 times more likely to result in a clean bowel when compared with polyethylene glycol alone (112893). The interpretation of these findings is limited by varied senna dosages and regimens. Additionally, 2 clinical studies that were not included in this meta-analysis show that senna is as effective or more effective than polyethylene glycol for improving bowel cleanse quality (15431,40088). Conversely, other studies show that polyethylene glycol is superior to senna (40086,74587,74606,74636). It is also unclear if taking senna with polyethylene glycol improves bowel cleansing when compared with polyethylene glycol alone (74583,74585). Some clinical studies show that senna is as effective as castor oil and bisacodyl for bowel cleansing (74548,74603,74624). Although taking senna alone is less effective than sodium phosphate (15431,74567,74570,74653,92712), some evidence suggests that taking a combination of senna, sodium picosulfate, and polyethylene glycol is more effective than sodium phosphate for bowel cleansing prior to colonoscopy (74538). Limited research has also assessed the benefit of adding senna to a preparation regimen for small bowel capsule endoscopy; however, it is unclear whether the addition of senna improves endoscopy outcomes when compared with the preparation regimen alone (96557). There is insufficient reliable information available about the effectiveness of senna for its other uses.

(Read more about SENNA)

POSSIBLY SAFE ...when used orally and appropriately, short-term. Tea prepared with alder buckthorn bark 2 grams has been used with apparent safety for up to 8 days (12). Only properly aged bark should be used, and the recommended dose should not be exceeded (12).

POSSIBLY UNSAFE ...when used orally for more than 8 to 10 days (12). In 1993 the FDA removed Generally Recognized As Safe (GRAS) status from alder buckthorn due to lack of safety data. Chronic use of anthraquinone laxatives, such as alder buckthorn, for 9 months or longer is associated with damage to gastrointestinal epithelial cells and pigmentation of the colonic mucosa, known as pseudomelanosis coli (30743,37266). There is some data linking this condition to an increased risk of colorectal cancer (30743,37266,37269), although there is also contradictory evidence that does not show a link (6138).

CHILDREN: LIKELY UNSAFE
when used orally in children younger than 12 years of age (12); avoid using.

PREGNANCY AND LACTATION: LIKELY UNSAFE
when used orally (12); avoid using.

(Read more about ALDER BUCKTHORN)

LIKELY UNSAFE ...when used orally; contraindicated in all but small doses (4). The fresh root can cause nausea, vomiting, and mucosal irritation (4,12). The blue flag oil is a mucous membrane irritant (4).

PREGNANCY AND LACTATION: LIKELY UNSAFE
when used orally (4,12); avoid using.

(Read more about BLUE FLAG)

POSSIBLY SAFE ...when used orally and appropriately, short-term. Cascara sagrada seems to be safe when used for less than one week (272,25023,40087). Cascara sagrada was formerly approved by the US Food and Drug Administration (FDA) as a safe and effective over-the-counter (OTC) laxative, but this designation was removed in 2002 due to a lack of supporting evidence (8229).

POSSIBLY UNSAFE ...when used orally, long-term. Using cascara sagrada for more than 1-2 weeks can lead to dependence, electrolyte loss, and hypokalemia (272).

CHILDREN: POSSIBLY UNSAFE
when used orally in children. Cascara sagrada should be used cautiously in children due to the risk of electrolyte loss and hypokalemia (272).

PREGNANCY:
Insufficient reliable information available; avoid using.

LACTATION: POSSIBLY UNSAFE
when used orally. Cascara sagrada is excreted into breast milk and might cause diarrhea (272).

(Read more about CASCARA SAGRADA)

LIKELY SAFE ...when the stalk is used in amounts commonly found in foods and when the root is used as a food flavoring. Rhubarb has Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY SAFE ...when the root or rhizome is used orally and appropriately in medicinal amounts for up to 2 years (92294,92295,92297). ...when the stalk is used orally and appropriately in medicinal amounts for up to 4 weeks (71351,71363,97920). ...when used topically and appropriately (10437,97919).

POSSIBLY UNSAFE ...when the leaf is used orally. Rhubarb leaf contains oxalic acid and soluble oxalate, which can cause abdominal pain, burning of the mouth and throat, diarrhea, nausea, vomiting, seizures, and death (17).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used in medicinal amounts, rhubarb root is a stimulant laxative; avoid using (12).

(Read more about RHUBARB)

LIKELY SAFE ...when used orally and appropriately, short-term. Senna is an FDA-approved nonprescription drug (8424,15429,15431,15442,40086,40088,74535,74545,74548,74562)(74567,74570,74583,74585,74586,74587,74593,74603,74606,74607)(74609,74613,74615,74624,74636,74639,74644,74650,74653,92711)(92712).

POSSIBLY UNSAFE ...when used orally long-term or in high doses. Long-term, frequent use, or use of high doses has been linked to serious side effects including laxative dependence and liver toxicity (13057,13095).

CHILDREN: LIKELY SAFE
when used orally and appropriately, short-term. Senna is an FDA-approved nonprescription drug for use in children 2 years and older. (15429,15434,15435).

CHILDREN: POSSIBLY UNSAFE
when used orally long-term or in high doses. Long-term, frequent use, or use of high doses has been linked to serious side effects including laxative dependence and liver toxicity (13057,13095,105956).

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately, short-term (15429,24480). POSSIBLY UNSAFE...when used orally long-term or in high doses. Long-term, frequent use, or use of high doses has been linked to serious side effects including laxative dependence and liver toxicity (13057,13095).

LACTATION: POSSIBLY SAFE
when used orally and appropriately, short term. Although small amounts of constituents of senna cross into breast milk, senna has been taken while breast-feeding with apparent safety. Senna does not cause changes in the frequency or consistency of infants' stools. (6026,15429,15436,15437,24482,24484,24485,24486,24487,74545).

(Read more about SENNA)

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Alder buckthorn has stimulant laxative effects. Theoretically, overuse of alder buckthorn might compound diuretic-induced potassium loss (19). There is some concern that people taking alder buckthorn along with potassium depleting diuretics might have an increased risk for hypokalemia.  Details Some diuretics that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), and hydrochlorothiazide (HCTZ, HydroDIURIL, Microzide), and others.

(Read more about ALDER BUCKTHORN)

(Read more about BLUE FLAG)

CORTICOSTEROIDS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, cascara sagrada might increase the risk of hypokalemia when taken with corticosteroids.  Details Cascara sagrada has stimulant laxative effects, and long-term use has been associated with hypokalemia (2,4).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = D Theoretically, cascara sagrada might decrease the effects of CYP3A4 substrates.  Details In vitro research suggests that cascara sagrada can induce CYP3A4 enzymes, albeit to a much lower degree than rifampin, a known CYP3A4 inducer (110704).

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, cascara sagrada might cause hypokalemia, potentially increasing the risk of digoxin toxicity.  Details Cascara sagrada has stimulant laxative effects, and long-term use has been associated with hypokalemia (4,19).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, cascara sagrada might increase the risk of hypokalemia when taken with diuretic drugs.  Details Cascara sagrada has stimulant laxative effects, and long-term use has been associated with hypokalemia (4,19).

STIMULANT LAXATIVES Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, cascara sagrada might have additive adverse effects when taken with stimulant laxatives.  Details Cascara sagrada has stimulant laxative effects and might compound fluid and electrolyte losses when taken with stimulant laxatives (19).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, cascara sagrada might increase the risk of bleeding when taken with warfarin.  Details Cascara sagrada has stimulant laxative effects (19). In some people, cascara sagrada can cause diarrhea. Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding.

(Read more about CASCARA SAGRADA)

CORTICOSTEROIDS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, frequent and high doses of rhubarb might increase the risk of hypokalemia when taken with corticosteroids.  Details Rhubarb has stimulant laxative effects. Overuse of rhubarb might compound corticosteroid-induced potassium loss (2,12).

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rhubarb with cyclosporine might reduce cyclosporine levels.  Details Animal research shows that co-administration of rhubarb decoction 0.25 or 1 gram/kg with cyclosporine 2.5 mg/kg, decreases cyclosporine maximum plasma concentration and overall exposure levels when compared with taking cyclosporine alone. The authors theorize that rhubarb might reduce cyclosporine bioavailability by inducing of P-glycoprotein and/or cytochrome P450 3A4 (92304). However, since rhubarb was administered as a single oral dose and enzyme induction usually occurs after multiple doses, it is possible that cyclosporine absorption was actually reduced via rhubarb's stimulant laxative effects (12). Also, the composition of the rhubarb decoction was not described.

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, overuse of rhubarb might increase the risk of adverse effects when taken with digoxin.  Details Rhubarb has stimulant laxative effects. Overuse of rhubarb might cause potassium depletion, increasing the risk of digoxin toxicity (12,19).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, frequent and high doses of rhubarb might increase the risk of hypokalemia.  Details Rhubarb has stimulant laxative effects. Overuse of rhubarb might cause potassium depletion and compound diuretic-induced potassium loss (12,19).

HEPATOTOXIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of rhubarb with potentially hepatotoxic drugs might increase the risk of developing liver damage.  Details Some animal research suggests that anthraquinones in rhubarb might have hepatotoxic effects (105960). Also, rhubarb use has been linked to at least 24 cases of liver injury, although details on the dose of rhubarb and duration of use in these cases is unclear (100963).

NEPHROTOXIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, long-term use of anthraquinones from rhubarb might increase the risk of nephrotoxicity when used with nephrotoxic drugs.  Details The anthraquinone constituents of rhubarb have been shown to induce nephrotoxicity in animal research (71322). Additionally, in a case report, a 23-year old female presented with kidney failure after taking 6 tablets of a proprietary slimming agent (found to contain the anthraquinones emodin and aloe-emodin from rhubarb) daily for 6 weeks and then adding diclofenac 25 mg 4 times daily for 2 days. The authors postulate that the anthraquinone constituents of rhubarb contributed to the renal dysfunction, and the addition of diclofenac, a nephrotoxic drug, led to renal failure (15257). Until more is known, advise patients to avoid taking rhubarb if they are taking other potentially nephrotoxic drugs.

STIMULANT LAXATIVES Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, rhubarb might increase the risk for fluid and electrolyte loss when taken with other stimulant laxatives.  Details Rhubarb has stimulant laxative effects (12). Concomitant use with stimulant laxatives might compound fluid and electrolyte loss (24427).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, excessive use of rhubarb might increase the risk of bleeding when taken with warfarin.  Details Rhubarb has stimulant laxative effects and can cause diarrhea (12,19). Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding. Advise patients who take warfarin not to take excessive amounts of rhubarb.

(Read more about RHUBARB)

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, senna might increase the risk of adverse effects when taken with digoxin.  Details Overuse/abuse of senna increases the risk of adverse effects from cardiac glycosides, such as digoxin, due to potassium depletion (15425).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, senna might increase the risk of hypokalemia when taken with diuretic drugs.  Details Overuse of senna might compound diuretic-induced potassium loss and increase the risk for hypokalemia (15425).

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, taking senna may interfere with the absorption of exogenous estrogens.  Details Some preliminary clinical evidence suggests that senna reduces the absorption of estradiol and decreases serum concentrations of estrone and estrone sulfate by decreasing intestinal transit time (74647,74651).

STIMULANT LAXATIVES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, senna might increase the risk for fluid and electrolyte loss when taken with other stimulant laxatives.  Details Senna is a stimulant laxative; concomitant use with other stimulant laxatives might compound fluid and electrolyte loss (19,15425).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, excessive use of senna might increase the effects of warfarin.  Details Senna has stimulant laxative effects and can cause diarrhea. Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding. In one case report, excessive use of senna for 3 weeks resulted in diarrhea, bloody stools, and an elevated INR of 11.9 (16530).

(Read more about SENNA)

General ...Orally, alder buckthorn seems to be well tolerated when properly aged bark is used appropriately for no more than 8 to 10 days (12). Adverse effects include cramp-like discomfort (2). Chronic use, especially for 9 months or longer, is associated with damage to gastrointestinal epithelial cells and pigmentation of the colonic mucosa, known as pseudomelanosis coli (30743,37266). There is some data linking this condition to an increased risk of colorectal cancer (30743,37266,37269), although there is also contradictory evidence which does not show a link (6138). Alder buckthorn has also been associated with potassium depletion, albuminuria, and hematuria when used orally (2).

Gastrointestinal ...Orally, adverse effects include cramp-like discomfort (2). Chronic use, especially for 9 months or longer, is associated with damage to gastrointestinal epithelial cells and pigmentation of the colonic mucosa, known as pseudomelanosis coli (30743,37266). The fresh bark contains free anthrone, which can cause severe vomiting. This constituent is destroyed by aging the bark naturally for one year or artificially with heat and aeration (2).

Genitourinary ...Orally, adverse effects to alder buckthorn include albuminuria and hematuria (2).

Oncologic ...Orally, there is also some data linking pseudomelanosis coli to an increased risk of colorectal cancer (30743,37266,37269), although there is also contradictory evidence which does not show a link (6138).

(Read more about ALDER BUCKTHORN)

General ...Orally, blue flag can cause nausea and vomiting, and the fresh root can irritate mucosa (4,19). Orally and topically, the volatile oil constituent of blue flag irritates mucous membranes and can cause lacrimation, eye inflammation, irritation of the throat, and headache (4).

Dermatologic ...Orally, the fresh blue flag root can irritate mucosa (4,19). Topically, the volatile oil constituent of blue flag irritates mucous membranes (4).

Gastrointestinal ...Orally, blue flag can cause nausea and vomiting and the fresh blue flag root can irritate mucosa (4,19). The volatile oil constituent of blue flag irritates mucous membranes and can cause irritation of the throat (4).

Neurologic/CNS ...Orally, the volatile oil constituent of blue flag can cause headache (4).

Ocular/Otic ...Orally and topically, the volatile oil constituent of blue flag can cause lacrimation and eye inflammation (4).

(Read more about BLUE FLAG)

General ...Orally, cascara sagrada seem to be well tolerated when used appropriately, short-term.
Most Common Adverse Effects:
Orally: Mild abdominal discomfort and cramps.
Serious Adverse Effects (Rare):
Orally: Hepatotoxicity. Fresh or improperly aged cascara sagrada bark can cause severe vomiting.

Endocrine ...Orally, long-term use of cascara sagrada can lead to potassium depletion (4).

Gastrointestinal ...Orally, cascara sagrada can commonly cause mild abdominal discomfort, colic, and cramps (4). In some cases, chronic use can cause pseudomelanosis coli. Pseudomelanosis coli (pigment spots in intestinal mucosa) is believed to be harmless, usually reverses with discontinuation, and is not directly associated with an increased risk of developing colorectal adenoma or carcinoma (6138).
Fresh or improperly aged cascara sagrada bark can cause severe vomiting due to the presence of free anthrone constituents (2,92307).

Genitourinary ...Orally, long-term use of cascara sagrada can lead to albuminuria and hematuria (4).

Hepatic ...There is some concern about potential liver problems with cascara sagrada. In some cases, cascara sagrada bark 750-1275 mg (containing approximately 21 mg cascaroside) daily in divided doses for three days resulted in cholestatic hepatitis, ascites, and portal hypertension. Symptoms resolved following discontinuation of cascara sagrada (6895,92306).

Musculoskeletal ...Orally, long-term use of cascara sagrada can lead to muscle weakness and finger clubbing (4).

Other ...Orally, long-term use of cascara sagrada can lead to cachexia (4).

(Read more about CASCARA SAGRADA)

General ...Orally, rhubarb root and stalk are well tolerated when used in food amounts and seem to be well tolerated when used in medicinal amounts. Rhubarb leaf contains oxalic acid and can be toxic. Topically, rhubarb seems to be well tolerated.
Most Common Adverse Effects:
Orally: Cramps, diarrhea, gastrointestinal discomfort, nausea, vomiting.
Topically: Rash.
Serious Adverse Effects (Rare):
Orally: Anaphylaxis.

Cardiovascular ...Orally, chronic use or abuse of rhubarb can cause arrhythmias (12).

Dermatologic ...Orally, rhubarb taken alone or in combination with other ingredients has been reported to cause rash (71315,71342). Topically, short term application of a specific product (Pyralvex) containing rhubarb, salicylic acid, and ethanol to the gums has been reported to cause slight burning and dark discoloration of the gums in approximately 1% of patients (71369). It is unclear if this effect is due to rhubarb, other ingredients, or the combination.

Endocrine ...Orally, chronic use or abuse of rhubarb can cause electrolyte loss (especially potassium), hyperaldosteronism, albuminuria, and edema (12).

Gastrointestinal ...Orally, rhubarb can cause cramp-like or spasmodic gastrointestinal discomfort, watery diarrhea, and uterine contractions (18). Rhubarb, alone or in combination with other ingredients, has also been reported to cause bloating, nausea, diarrhea, vomiting, and stomach upset or pain in clinical studies. Diarrhea is more common with a starting dose of at least 3 grams of extract (71315,71329,71339,71340,71341,71342,71373,92300). Chronic use or abuse of rhubarb can cause inhibition of gastric motility and pseudomelanosis coli (pigment spots in the intestinal mucosa) (12,6138).
Although some research suggests that rhubarb and other anthranoid laxatives might increase the risk of colorectal cancer due to pseudomelanosis coli (30743), more recent research suggests that this condition is harmless, typically reversed with rhubarb discontinuation, and not associated with an increased risk for colorectal adenoma or carcinoma (6138).

Hematologic ...Orally, chronic use or abuse of rhubarb can cause hematuria (12).

Hepatic ...Orally, chronic use of anthraquinone-containing products, such as rhubarb, has been associated with hepatotoxicity (15257). Use of rhubarb specifically has been linked to at least 24 reports of liver injury, although details on the dose of rhubarb and duration of use in these cases are not clear (100963). In one clinical study, rhubarb, taken in combination with other ingredients, has been reported to cause mild to moderate elevations of serum alanine aminotransferase (71315).

Immunologic ...Orally, rhubarb has rarely been reported to cause anaphylaxis (18).

Musculoskeletal ...Orally, chronic use or abuse of rhubarb can cause accelerated bone deterioration and muscular weakness (12).

Renal ...Orally, chronic use or abuse of rhubarb can cause electrolyte loss (especially potassium), albuminuria, hematuria, dehydration, and nephropathies (12). There is one case report of renal failure in a patient who took a product containing rhubarb for six weeks. The patient presented with renal failure two days after starting diclofenac, which is known to have nephrotoxic effects. It is hypothesized that the combination of diclofenac with the anthraquinone constituents of rhubarb precipitated renal dysfunction (15257).

(Read more about RHUBARB)

General ...Orally, senna is generally well-tolerated when used short-term in appropriate doses.
Most Common Adverse Effects:
Orally: Abdominal pain and discomfort, cramps, diarrhea, flatulence, nausea, fecal urgency, and urine discoloration.
Serious Adverse Effects (Rare):
Orally: Skin eruptions.

Cardiovascular ...Excessive use can cause potassium depletion and other electrolyte abnormalities (15425). In theory, this could cause potentially dangerous changes in heart rhythm. A small decrease in heart rate was seen in one clinical study (74587).

Dermatologic ...In adults, there are rare case reports of skin eruptions associated with senna, including erythema multiforme, fixed drug eruption, lichenoid reaction, toxic epidermal necrolysis, urticaria, photosensitivity, and contact dermatitis (96558). Infants and young children given senna products have experienced contact reactions on the buttocks due to prolonged exposure to stool while wearing a diaper overnight. These reactions range from erythema with small blisters, to large fluid-filled blisters with skin sloughing, as occurs with second degree burns (96559). In a case series of children treated with senna for chronic constipation, burn-like reactions occurred in 2.2%, typically with higher doses (mean 60 mg/day, range 35.2 to 150 mg/day) (96558,96559). These reactions can be avoided by giving senna early in the day, so that bowel movements occur at a time when diapers can be changed quickly (96559).

Gastrointestinal ...Orally, senna can cause abdominal pain and discomfort, cramps, bloating, flatulence, nausea, fecal urgency, and diarrhea (15427,15434,15435,15436,15439,15440,15441,105955). Chronic use has also been associated with "cathartic colon," radiographically diagnosed anatomical changes to the colon such as benign narrowing, colonic dilation, and loss of colonic folds (15428). The clinical relevance of these findings is unclear. Chronic use can also cause pseudomelanosis coli (pigment spots in intestinal mucosa) which is harmless, usually reverses with discontinuation, and is not associated with an increased risk of developing colorectal adenoma or carcinoma (6138). The cathartic properties of senna leaf are greater than the fruit (15430). Thus, the American Herbal Products Association only warns against long-term use of senna leaf (12).

Hepatic ...Chronic liver damage, portal vein thrombosis, and hepatitis have been reported following oral use of senna alkaloids, such as in tea made from senna leaves (13057,13095,41431,74560,74564,74584,105956). There is a case report of hepatitis in a female who consumed moderate amounts of senna tea. The patient was a poor metabolizer of cytochrome P450 2D6 (CYP2D6). It's thought that moderate doses of senna in this patient led to toxic hepatitis due to the patient's reduced ability to metabolize and eliminate the rhein anthrone metabolites of senna, which are thought to cause systemic toxicity (13057). There is also a case of liver failure, encephalopathy, and renal insufficiency in a female who consumed 1 liter/day of senna tea, prepared from 70 grams of dried senna fruit, over 3 years (13095). In another case report, a 3-year-old female presented with hepatitis that led to pancytopenia after drinking tea made from 2-3 grams dry senna leaves three times or more weekly for over one year (105956).

Immunologic ...In one case report, a 19-year-old male developed anaphylaxis with dyspnea, facial edema, and hives. This reaction was determined to be caused by the senna content in a specific combination product (Delgaxan Plus, Pompadour Ibérica) that the patient ingested (105957).

Musculoskeletal ...Hypertrophic osteoarthropathy, finger clubbing, cachexia, and tetany have been reported from excessive oral senna use in humans (15426,74580,74582,74620,74625).

Renal ...Nephrocalcinosis has been reported as a result of oral senna overuse (74582).

(Read more about SENNA)