Kwan Loong Medicated Oil by Haw Par Healthcare Limited

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there is interest in using topical eucalyptus for acne, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Asthma. A small clinical study suggests that taking the eucalyptol constituent of eucalyptus orally might have a steroid-sparing effect in some patients with asthma. Details: Preliminary clinical research in patients with steroid-dependent asthma shows that taking eucalyptol, a constituent of eucalyptus oil, 200 mg three times daily orally for 12 weeks, allows for an average reduction in prednisolone doses of 36%, compared with a 7% reduction in those taking placebo (13302).
• Bronchitis. Oral eucalyptol has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some clinical research in patients with chronic bronchitis shows that taking a specific combination product containing eucalyptol and extracts of pine and lime (Myrtol standardized, MYS, Gelomyrtol forte) 900 mg daily orally for at least 1 month decreases the proportion of patients with acute exacerbations by 72%, compared with 53% for those taking placebo (48925). In patients with acute bronchitis, receiving the same product in a dose of 1200 mg daily for 14 days is associated with a reduction in symptoms in all but 1% of patients, compared with 32% of patients receiving placebo (48932).
• Burns. Although there is interest in using topical eucalyptus for burns, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Cancer. Although there is interest in using oral eucalyptus for cancer, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Chronic obstructive pulmonary disease (COPD). A small clinical study suggests that the eucalyptol constituent of eucalyptus might reduce acute exacerbations in patients with stable COPD. Details: Clinical research in adults with stable, moderate to severe COPD shows that adding eucalyptol, 200 mg three times daily, to conventional therapy for 6 months, including the winter season, reduces the proportion of patients experiencing acute exacerbations from 46% to 28% when compared with placebo (104960).
• Cough. Oral eucalyptus oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of four clinical studies in patients with cough associated with bronchitis or upper respiratory tract infection shows that taking eucalyptus oil, either in combination with pine and lime essential oils (Myrtol or Gelomyrtol) or with Origanum syriacum, peppermint, and rosemary essential oils, daily for up to 6 months increases the likelihood of improvement or resolution of cough symptoms by 45% when compared with placebo (110095).
• Dental plaque. Using chewing gum containing eucalyptus extract might reduce dental plaque. Details: Preliminary clinical research shows that chewing gum containing 0.3% to 0.6% eucalyptus extract 3-5 times daily for 4 days to 12 weeks reduces dental plaque when compared with placebo (49010,92863).
• Diabetes. Although there is interest in using oral eucalyptus for diabetes, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Endotracheal intubation-associated adverse effects. It is unclear if nebulized eucalyptus oil is beneficial for prevention of complications associated with endotracheal intubation. Details: A small clinical study in Iranian patients intubated and receiving care in the intensive care unit shows that nebulizing 4 mL of eucalyptus 5% oil in 6 mL of normal saline every 8 hours for 3 days increases oxygen saturation and decreases peak inspiratory pressure, but does not affect the level of consciousness as measured using the Glasgow Coma Scale, when compared with nebulized normal saline (110096).
• Genital herpes. Although there is interest in using topical eucalyptus for genital herpes, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Gingivitis. Using chewing gum containing eucalyptus extract might improve gingivitis. Details: Preliminary clinical research shows that chewing gum containing 0.4% to 0.6% eucalyptus extract five times daily for 4 days improves gingivitis when compared with placebo (92863).
• Gonorrhea. Although there is interest in using oral eucalyptus for gonorrhea, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Halitosis. Using chewing gum containing eucalyptus extract might improve halitosis. Details: Preliminary clinical research shows that chewing gum containing 0.4% to 0.6% eucalyptus extract five times daily for 12 weeks significantly improves halitosis and coating of the tongue when compared with placebo (92863).
• Headache. Topical eucalyptus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that applying a combination of peppermint oil, eucalyptus oil, and ethanol topically to the forehead and temples does not affect headache pain, but improves cognitive performance and produces relaxation, when compared with placebo (3801).
• Influenza. Although there is interest in using oral or inhaled eucalyptus for influenza, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Lice. Topical eucalyptus oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with head lice shows that applying eucalyptus oil 11% and lemon tea tree oil 1% (MOOV Head Lice Solution, Ego Pharmaceuticals Pty Ltd.) reduces the ex-vivo egg hatching rate by only 3%, compared with a 44% reduction with tea tree oil and lavender oil (NeutraLice Natural Lotion), and a 68% reduction with benzyl alcohol, mineral oil, and triethanolamine (NeutraLice Advance) (19188). However, other research in elementary school aged children shows that applying the MOOV Head Lice Solution combination product to the scalp for 10 minutes, once weekly for 3 weeks, is more effective than applying pyrethrins and piperonyl butoxide once weekly for 2 weeks. At 7 days after the last application, 71% of children treated with the eucalyptus formulation were still free of lice, compared with 33% of children in the control group (98492).
• Onychomycosis. Although there is interest in using topical eucalyptus for onychomycosis, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Oral mucositis. Although there is interest in using topical or oral eucalyptus for oral mucositis, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Osteoarthritis. Although there is interest in using topical eucalyptus for osteoarthritis, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Rheumatoid arthritis (RA). It is unclear if inhaled eucalyptus oil is beneficial in patients with RA. Details: A small clinical study in patients with RA shows that aromatherapy with eucalyptus essential oil, delivered by applying 2 mL of oil to pads attached to clothing for 5 minutes three times daily for 1 month, reduces pain and improves quality of life when compared with placebo (110094).
• Rhinosinusitis. Although there is interest in using inhaled eucalyptus for rhinosinusitis, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Tinea corporis. Although there is interest in using topical eucalyptus for tinea corporis, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Tuberculosis. Although there is interest in using oral eucalyptus for tuberculosis, there is insufficient reliable information about the clinical effects of eucalyptus for this condition.
• Ventilator-associated pneumonia (VAP). It is unclear if eucalyptus is beneficial for the prevention of VAP. Details: Preliminary clinical research in ventilated adult patients shows that nebulizing a 2% eucalyptus solution for about 20 minutes every 8 hours reduces the incidence of late bacterial pneumonia (occurring more than 96 hours after initiation of ventilation) from 58% to 30% when compared with placebo. In those patients who developed VAP, the onset occurred approximately 3 days later, on average, in the eucalyptus group than in the placebo group (104958).
• Wound healing. Although there is interest in using topical eucalyptus for wound healing, there is insufficient reliable information about the clinical effects of eucalyptus for this condition. More evidence is needed to rate eucalyptus for these uses.

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LIKELY EFFECTIVE

• Irritable bowel syndrome (IBS). Oral enteric-coated peppermint oil is conditionally recommended by the American College of Gastroenterology (ACG) for the relief of global IBS symptoms, such as abdominal pain. Details: The ACG conditionally recommends the use of peppermint for the relief of global IBS symptoms. This recommendation is based on an available meta-analysis of generally low-quality clinical research (105124). Several clinical trials and meta-analyses show that taking enteric-coated peppermint oil 1-2 capsules orally two to four times daily reduces abdominal pain, distention, flatulence, and bowel movements in patients with IBS. Each capsule provides approximately 0.2 mL of peppermint oil or 180-225 mg peppermint oil. Most trials have used specific products (Colpermin, Tillotts Pharma; Mintoil, Cadigroup; Ibgard, IM HealthScience, Tempocol) (3802,3803,4469,11778,11779,17681,17682,68467,68515,68522)(68603,68604,68605,96360,99493,109980). The most recent meta-analysis to date shows that four patients would need to take peppermint oil to prevent one patient from having persistent IBS symptoms, and seven patients would need to take peppermint oil to prevent one patient from having abdominal pain. However, the individual studies included in the analysis lasted no more than 12 weeks (109980); any long-term effects are unclear. Although most studies have shown benefit for reducing symptoms, some older studies have found no significant effect (11777,11789) or only short-term benefits (68620). Also, a well-designed study shows that taking peppermint oil capsules designed for either small intestinal release (enteric-coated) or ileocolonic release does not increase the number of people with at least a 30% decrease in abdominal pain over a period of 4 weeks, although symptoms are modestly reduced when compared with placebo (102602). Another clinical trial in patients with moderate to severe IBS shows that taking a specific enteric-coated formulation of peppermint oil (Pepogest; Nature's Way) 180 mg three times daily for 6 weeks does not further improve symptom severity when compared with placebo. However, both groups experienced a large improvement on the IBS-Severity Scoring System (IBS-SSS) and the IBS Global Improvement Scale (107955). The validity of these findings is limited due to lost data and inconsistent follow-up; additionally, adverse effects occurred more frequently in the peppermint oil group. The reasons for these negative findings are unclear but may include short treatment durations and the use of different formulations; additionally, IBS is comprised of various subtypes and symptoms that can range in severity and presentation, which may alter treatment response. Some clinical research has also evaluated a specific combination product (Atrantil, KBS Research) containing peppermint leaf, red quebracho extract, and conker tree extract. Taking this product as needed for 2 weeks seems to reduce constipation and bloating when compared to baseline in patients with constipation-predominant IBS (95429,95430). It is unclear if the effects of this product are due to peppermint, the other ingredients, or the combination.

POSSIBLY EFFECTIVE

• Barium enema-related colonic spasm. Rectal peppermint, as part of barium enema preparations, seems to reduce colonic spasms during examination. Oral peppermint also seems to be beneficial. Details: Rectal use of peppermint oil, added as an ingredient in barium enema preparations, seems to relax the colon during barium enema examination and reduce the percentage of patients who experience colonic spasms by about 25% to 30% (6739,6749,12009). Adding peppermint oil to the barium enema seems to be at least as effective as using systemic scopolamine (Buscopan). Adding peppermint oil to the barium solution also does not seem to impair image quality (12009). Some clinical research also shows that taking peppermint oil orally before the start of a double-contrast barium enema examination decreases spasms and might also increase diagnostic quality (14467).
• Chemotherapy-induced nausea and vomiting (CINV). Oral and inhaled peppermint seem to reduce nausea and vomiting in patients with CINV. Details: Clinical research shows that adding peppermint oil, 40 drops in 20 mL water, every 8 hours following chemotherapy treatment to treatment with standard antiemetics reduces the severity of nausea, vomiting, and anorexia by moderate to large amounts over 48 hours when compared with a plain water placebo (105123). The use of peppermint oil aromatherapy has also been investigated. Clinical research shows that adding 2 drops of peppermint oil to a cool, damp washcloth for use on the neck as aromatherapy for about 30 minutes helps relieve chemotherapy-induced nausea by a small amount when compared with a washcloth without peppermint oil (102603). Additional clinical research in patients receiving standard antiemetics after chemotherapy shows that applying one drop of peppermint oil below the nose three times daily for 5 days reduces the severity of nausea and the frequency of nausea, vomiting, and retching by a moderate to large amount when compared with the antiemetics alone. These parameters were not improved following treatment with cisplatin (105122). In children with acute leukemia, a small clinical study shows that aromatherapy with 2 drops of peppermint oil and 3 drops of lemon oil in 80 mL of water diffused 30 minutes prior to and 2 and 4 hours after chemotherapy once weekly for 4 weeks decreases the severity of nausea, vomiting, and retching, and improves quality of life scores when compared with diffused water or no intervention (112015). The validity of these findings is limited by the use of patient-reported outcomes.
• Dyspepsia. Oral peppermint, in combination with caraway and possibly other ingredients, seems to reduce symptoms of dyspepsia. It is unclear if oral peppermint alone is beneficial. Details: Some clinical research shows that taking specific products containing peppermint and caraway oil (Enteroplant, Dr Willmar Schwabe Pharmaceuticals; Menthacarin, Dr Willmar Schwabe GmbH & Co.) improves quality of life and reduces symptoms of dyspepsia, including feelings of fullness, pain, and mild gastrointestinal spasms (6740,6741,10075,96344,102600). A meta-analysis of three of these clinical studies shows that taking this combination product 2-3 times daily for 4 weeks modestly reduces abdominal pain when compared with placebo (110091). Taking this combination twice daily for 4 weeks also improves postprandial distress syndrome and epigastric pain syndrome, two subtypes of dyspepsia, when compared with placebo (96344). The combination of enteric-coated peppermint oil 90 mg and caraway oil 50 mg appears to be comparable to cisapride for relieving dyspepsia when taken 2-3 times daily for up to 4 weeks (6740,6741,10075). However, most trials investigating this combination are small and/or of overall low quality (102600). A specific combination product containing peppermint leaf (Iberogast, Steigerwald Arzneimittelwerk GmbH) also seems to improve symptoms of dyspepsia. The combination includes peppermint leaf plus clown's mustard plant, German chamomile, caraway, licorice, milk thistle, angelica, celandine, and lemon balm (7049). A meta-analysis of studies using this combination product shows that taking 1 mL orally three times daily over a period of 4 weeks reduces the severity of acid reflux, epigastric pain, cramping, nausea, and vomiting when compared with placebo (13089). A similar combination product containing extracts from peppermint leaf, clown's mustard plant, German chamomile flower, caraway, licorice root, and lemon balm (STW 5-II, Steigerwald Arzneimittelwerk GmbH) 1 mL taken three times daily for up to 8 weeks eliminates gastrointestinal symptoms in 40% more dyspepsia patients when compared with placebo (12724).
• Endoscopy-associated adverse effects. Intraluminal peppermint seems to reduce spasticity during an endoscopy. It is unclear if oral peppermint is beneficial for reducing adverse effects related to endoscopy. Details: A meta-analysis of four clinical trials show that peppermint oil, administered orally or intraluminally, reduces the incidence of spasticity by about 41% when compared with placebo in patients undergoing endoscopy, with severe spasticity occurring at about 30% the rate of those taking placebo. However, there was no effect on subjective pain (102604). Individual clinical studies show that intraluminal peppermint oil can reduce both pain and spams in patients undergoing endoscopy (18220,68371,68395,68445,68532). However, there are limitations with this form of administration, including cost and practicality, which has led to interest in the use of oral formulations (104221). Studies evaluating oral extended-release peppermint have been conflicting. While one study shows that a specific extended-release peppermint oil product (Colpermin) 187 mg or 0.2 mL taken orally 4 hours prior to a colonoscopy reduces procedure time, pain, and spasticity (68532), a study using another specific extended-release peppermint oil (IBGard) did not show an effect on colonic spasms, procedure time, or adenoma detection rate when compared with placebo (104221). These differing outcomes may be due to timing of administration. The study that showed benefit administered the treatment 4 hours prior to endoscopy, whereas the study showing no benefit administered the treatment only 1 hour prior. This suggests that extended-release peppermint may need to be administered at least 4 hours prior to the procedure to allow for adequate colonic release (68532,102604,104221).
• Nipple fissures. Topical peppermint seems to reduce cracked skin and pain in the nipples due to breastfeeding. Details: Clinical research shows that topical application of peppermint oil in gel or water reduces cracked skin and pain in the nipple area from breastfeeding when compared with using placebo, lanolin, or the expressed breast milk technique (68454,68462). Other research shows that applying peppermint oil in cream immediately after breastfeeding for 2 weeks decreases pain and trauma in the nipple area similarly to the topical application of dexpanthenol or lanolin (96365).
• Pressure ulcers. Topical peppermint seems to reduce the risk of pressure ulcers. Details: Clinical research in bedridden patients shows that prophylactic application of a topical gel containing peppermint oil 0.2% three times daily for up to 14 days results in pressure injuries in about 23% of patients compared with 77% of those given a placebo gel (102605).
• Tension headache. Topical peppermint seems to relieve tension headaches. Details: Clinical research shows that topical application of peppermint oil 10% relieves tension headaches when compared with placebo (3801,6190).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Abdominal pain. Although there has been interest in using oral peppermint for abdominal pain, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Anxiety. It is unclear if inhaled peppermint oil is beneficial for reducing anxiety. Details: A clinical trial in patients presenting to the emergency department for an acute coronary syndrome event shows that placing 3 drops of peppermint oil on a cotton ball and inhaling for 1 hour improves anxiety and respiratory rate when compared with baseline or placebo (107958). Due to the single-dose nature of this study, the effects of repeated inhalation of peppermint oil are unclear.
• Breast cancer-related hot flashes. It is unclear if topical peppermint is beneficial for reducing hot flashes in patients with breast cancer. Details: Preliminary clinical research shows that using a spray containing a combination of peppermint and neroli hydrolat does not alleviate hot flashes in most patients receiving chemotherapy for breast cancer when compared with using a plain water spray (68481).
• Cognitive function. It is unclear if inhaled peppermint oil is beneficial for improving cognitive function. Details: Preliminary clinical research shows that inhalation of peppermint oil slightly improves memory and the performance of cognitive tasks such as typing, alphabetization, and ordering, but not attention and speed of task completion, when compared with control (56954,68416,68466).
• Common cold. Although there has been interest in using oral, topical, or inhaled peppermint for the common cold, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Dental plaque. Topical peppermint has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that rinsing the mouth for one minute with 10 mL of a specific combination product (HiOra, Himalaya Herbal Healthcare) containing peppermint oil and numerous other ingredients twice daily for two days reduces plaque index or plaque area when compared with placebo; however, it was not as effective as chlorhexidine 0.2% solution (68530). It is unclear if these effects are due to peppermint oil, other ingredients, or the combination.
• Diffuse esophageal spasm. It is unclear if oral peppermint oil is beneficial for diffuse esophageal spasm. Details: A small exploratory study in adults with diffuse esophageal spasm shows that drinking a solution of peppermint oil, 5 drops in 10 mL of water, can resolve esophageal contractions when compared with baseline (13415). The validity of this finding is limited by the lack of a comparator group.
• Dysmenorrhea. It is unclear if oral peppermint oil is beneficial for reducing menstrual pain. Details: Preliminary clinical research shows that taking three capsules of peppermint oil (Colpermin; Tillotts Company or Razak company) daily for 3 days, starting on the first day of menstruation, is as effective as mefenamic acid 250 mg three times daily for reducing pain, and more effective for reducing nausea and vomiting, associated with dysmenorrhea. However, mefenamic acid was more effective for reducing bleeding and analgesic use (105125).
• Fatigue. It is unclear if inhaled peppermint oil improves fatigue in patients with cardiac disease. Details: A clinical trial in hospitalized patients with various forms of cardiac disease shows that placing 3 drops of peppermint oil on a cotton ball and inhaling for 20 minutes nightly for 7 days improves fatigue scores when compared with placebo. These improvements were similar to those seen with lavender oil inhalation. Fatigue scores decreased by 24 and 21 points in the peppermint and lavender groups, respectively, compared with a 2-point reduction in the placebo group (107959). The validity of these findings is limited due to the short duration of treatment.
• Halitosis. Peppermint has only been evaluated in combination with other ingredients as a mouthwash; its effect when used alone is unclear. Details: Preliminary clinical research shows that rinsing the mouth with a specific combination of tea tree oil, peppermint, and lemon essential oil once for three minutes improves breath smell when compared with placebo or benzydamine hydrochloride (19177).
• Insomnia. It is unclear if inhaled peppermint oil is beneficial for insomnia. Details: Preliminary clinical research in cancer patients shows that receiving aromatherapy as three drops of peppermint oil applied to a cotton ball and attached to the collar for 20 minutes at bedtime for one week improves sleep when compared with baseline. However, it seems to be no better than using lavender oil aromatherapy or using a control of lavender oil 1% (103063).
• Menopausal symptoms. Although there has been interest in using inhaled peppermint oil for menopausal symptoms, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Migraine headache. It is unclear if intranasal peppermint oil is beneficial for migraine headache. Details: Preliminary clinical research shows that using 1-2 doses of intranasal peppermint oil 1.5% (Poursina Company) at the start of migraine pain is as effective as intranasal lidocaine 4%, and more effective than placebo, for reducing migraine headache intensity. Approximately 42% of those using peppermint oil indicated a high level of headache reduction, compared with 42% of those using lidocaine and 5% of those using placebo. Also, pain relief was felt within 5 minutes in more patients using peppermint than placebo (105126). However, it is unclear if participants were truly blinded to the use of peppermint oil.
• Mosquito repellent. Although there has been interest in using topical peppermint oil as a mosquito repellent, there is insufficient reliable information about the clinical effects of peppermint for this purpose.
• Myalgia. Although there has been interest in using topical peppermint oil for myalgia, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Oral mucositis. Topical peppermint has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in adults undergoing stem cell transplantation shows that using an oral rinse containing peppermint oil and German chamomile three times daily, in addition to standard treatment with sodium chloride and chlorhexidine, reduces the duration and severity of mucositis and the use of narcotic analgesics when compared with placebo and standard treatment. However, this oral rinse does not reduce or delay the occurrence of mucositis or affect the duration of hospitalization (96363). Another small clinical study in adults with head and neck cancers undergoing radiation shows that rinsing with 5 mL of a polyherbal mouthwash containing peppermint oil, German chamomile, aloe vera, and honey for 1 minute 3 times daily for 6 weeks reduces oral mucositis incidence, severity, and pain when compared with chlorhexidine 0.2% and placebo (111291). Clinical research in adults receiving treatment with 5-fluorouracil shows that using an oral rinse containing peppermint, sage tea, and thyme in addition to basic oral care, starting on the first day of chemotherapy and continuing for 14 days, delays the onset of mucositis, but not the rate or severity of mucositis, when compared with basic oral care alone (96364). It is unclear if these effects are due to peppermint oil, other ingredients, or the combinations.
• Osteoarthritis. Although there has been interest in using topical peppermint oil for osteoarthritis, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Pain (acute). It is unclear if inhaled peppermint oil is beneficial for acute pain. Details: Preliminary clinical research in cardiac patients shows that peppermint oil aromatherapy reduces pain associated with intravenous catheterization by a small amount when compared with a distilled water control (102601).
• Postherpetic neuralgia. Although there has been interest in using topical peppermint oil for postherpetic neuralgia, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Postoperative ileus. It is unclear if oral peppermint oil is beneficial for the prevention of postoperative ileus. Details: Clinical research shows that taking a specific peppermint oil product (Colpermin, Tillotts Pharma) as two capsules three times daily for 5 days after routine gynecological surgery does not prevent postoperative abdominal distension and dyspepsia when compared with placebo (68602). Conversely, a small clinical study in patients undergoing elective cesarean section shows that taking 20 drops of peppermint oil 4 hours after surgery and then hourly for a total of three doses reduces the time to first bowel sounds by around 3.3 hours, first flatulence by 4.4 hours, and first stool by 5 hours when compared with placebo (110092).
• Postoperative nausea and vomiting (PONV). Some preliminary clinical studies suggest that inhaled peppermint may be beneficial for PONV. However, it is unclear if the benefit is due to aromatherapy or improved breathing patterns. Details: Some preliminary clinical research shows that using peppermint aromatherapy helps relieve postoperative nausea (3804,13415,68524,104219,104220). Inhaling peppermint oil 10% and 30% as aromatherapy reduces the severity of nausea when compared with placebo, with no significant difference between concentrations (104220). Small clinical trials show improvement in PONV within the first 4 hours after surgery. However, this effect diminishes beyond 4 hours (104219). Other preliminary clinical research shows that peppermint oil aromatherapy is no more effective for reducing postoperative nausea than inhaling isopropyl alcohol or saline (13416,68529). It is possible that any relief of postoperative nausea observed with peppermint aromatherapy results from improved breathing patterns after surgery rather than peppermint oil itself (13416,90512). One small study shows that inhaling peppermint oil while practicing controlled breathing does not appear to relieve PONV better than practicing controlled breathing alone (90512). Some preliminary clinical research shows that inhaling vapors from a mixture of peppermint, ginger, spearmint, and cardamom essential oils reduces symptoms of postoperative nausea in approximately 15% more patients when compared with inhaling ginger essential oils alone, and in approximately 43% more patients when compared with inhaling saline (89888). However, it is not clear if the effect is due to peppermint, the other oils, or the combination.
• Pre-procedural anxiety. It is unclear if inhaled peppermint oil is beneficial for reducing anxiety prior to a medical procedure. Details: Preliminary clinical research in cardiac patients shows that peppermint oil aromatherapy does not reduce anxiety associated with intravenous catheterization when compared with a distilled water control (102601).
• Pregnancy-induced nausea and vomiting. Inhaled peppermint oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that aromatherapy with a mixture of 5% lemon and 5% peppermint essential oils modestly reduces the intensity of nausea and vomiting on days 2-4, but not day 1, when compared with placebo aromatherapy. When nauseated, patients placed three drops of the essential oil mixture (Barij Essence Co.) onto a cotton ball held 3 cm from the nose. This action could be repeated after 5 minutes if needed (105121).
• Pruritus. Some preliminary clinical studies suggest that topical peppermint oil improves itching of various etiologies. Details: Preliminary clinical research in adults with renal, hepatic, or diabetic pruritus shows that topical application of peppermint oil 5% in petrolatum twice daily for 2 weeks improves symptoms of pruritus when compared with petrolatum alone (96361). Preliminary clinical research in patients with severe or intractable pruritus secondary to burn scars shows that applying a specific product (Chongqing No.1, CQ-01, MJ Medical Gel Systems Ltd.) containing peppermint oil 3.6%, menthol 1.4%, and methyl salicylate 2.5%, covered with gauze for 24 hours, reduces the severity of pruritus for up to 7 days after application when compared with hydrogel covered with gauze or with gauze alone (96362). Preliminary clinical research in females experiencing itchy skin due to intrahepatic cholestasis of pregnancy also shows that applying peppermint oil 0.5% in sesame oil twice daily for 2 weeks reduces pruritus severity approximately 1.8-fold when compared with sesame oil alone (89478).
• Small intestinal bacterial overgrowth (SIBO). Although there has been interest in using oral peppermint for SIBO, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Stress. It is unclear if inhaled peppermint oil is beneficial for stress. Details: Clinical research shows that peppermint aromatherapy decreases physical and perceived levels of stress when compared with baseline (68422,68517). A small clinical study in adults undergoing a virtual reality (VR) driving scenario to test road rage shows that exposure to peppermint oil (Pure Essential Oil of Peppermint, Tisserand Aromatherapy) 5 drops via fan diffuser improves aggressive driving behavior scores but does not seem to improve self-reported stress, aggression, alertness, happiness, or calmness when compared with controls that did not receive aromatherapy during the VR session (112017).
• Toothache. Although there has been interest in using topical peppermint oil for toothache, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Urticaria. Although there has been interest in using topical peppermint oil for urticaria, there is insufficient reliable information about the clinical effects of peppermint for this condition. More evidence is needed to rate peppermint for these uses.

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LIKELY SAFE ...when used orally in amounts commonly found in foods. Eucalyptus has Generally Recognized As Safe status (GRAS) for use in foods as a flavoring in the US (4912).

POSSIBLY SAFE ...when eucalyptol, a constituent of eucalyptus oil, is used orally and appropriately. Eucalyptol appears to be safe for up to 12 weeks (13302).

POSSIBLY UNSAFE ...when the undiluted oil is used topically. Prolonged or widespread exposure has caused neurotoxicity (12869). There is insufficient reliable information available about the safety of diluted eucalyptus oil when used topically.

LIKELY UNSAFE ...when the undiluted oil is ingested orally. Ingesting 3.5 mL of undiluted oil can be fatal in adults (12867). There is insufficient reliable information available about the safety of eucalyptus oil when inhaled as aromatherapy or when eucalyptus leaf is used orally in medicinal amounts.

CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in foods. Eucalyptus has Generally Recognized As Safe (GRAS) status for use in foods in the US (4912).

CHILDREN: LIKELY UNSAFE
when eucalyptus oil is used orally (12867,49002,107493,107495). ...when eucalyptus oil is used topically in infants and young children. There are reports of neurotoxicity in infants and young children exposed to topical eucalyptus oil. In one of these cases, a 12-month-old child was bathed in water containing eucalyptus oil and other essential oils; in another case, a child had a dressing containing eucalyptus oil applied every 2-4 hours daily for 2 days (12868,12869). ...when eucalyptus solutions are inhaled using a vaporizer (49002).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (4912). There is insufficient reliable information available about the safety of medicinal amounts of eucalyptus oil; avoid using.

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LIKELY SAFE ...when peppermint oil is used orally, topically, or rectally in medicinal doses. Peppermint oil has been safely used in multiple clinical trials (3801,3804,6190,6740,6741,10075,12009,13413,14467,17681)(17682,68522,96344,96360,96361,96362,96363,96364,96365,99493).

POSSIBLY SAFE ...when peppermint leaf is used orally and appropriately, short-term. There is some clinical research showing that peppermint leaf can be used safely for up to 8 weeks (12724,13413). The long-term safety of peppermint leaf in medicinal doses is unknown. ...when peppermint oil is used by inhalation as aromatherapy (7107). There is insufficient reliable information available about the safety of using intranasal peppermint oil.

CHILDREN: POSSIBLY SAFE
when used orally for medicinal purposes. Enteric-coated peppermint oil capsules have been used with apparent safety under medical supervision in children 8 years of age and older (4469).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (96361). There is insufficient information available about the safety of using peppermint in medicinal amounts during pregnancy or lactation; avoid using.

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AMPHETAMINES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, inhaling eucalyptol may reduce the effectiveness of amphetamines.  Details Animal research suggests that inhaling eucalyptol may reduce the levels of amphetamines in the blood (48987).

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, eucalyptus leaf might increase the risk of hypoglycemia.  Details Animal research suggests that eucalyptus leaf might have hypoglycemic activity, and might have additive effects when used with antidiabetes drugs (12871).

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, eucalyptus might increase the levels of CYP1A2 substrates.  Details In vitro research suggests that eucalyptus oil might inhibit CYP1A2, although this has not been reported in humans (12479).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, eucalyptus might increase the levels of CYP2C19 substrates.  Details In vitro research suggests that eucalyptus oil might inhibit CYP2C19, although this has not been reported in humans (12479).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, eucalyptus might increase the levels of CYP2C9 substrates.  Details In vitro research suggests that eucalyptus oil might inhibit CYP2C9, although this has not been reported in humans (12479).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, eucalyptus might increase the levels of CYP3A4 substrates.  Details In vitro research suggests that eucalyptus oil might inhibit CYP3A4, although this has not been reported in humans (12479).

PENTOBARBITAL (Nembutal) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, inhaling eucalyptol might reduce the effectiveness of pentobarbital.  Details Animal research suggests that inhaling eucalyptol reduces the level of pentobarbital that reaches the brain (48987).

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CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint oil might increase the levels and adverse effects of cyclosporine.  Details In animal research, peppermint oil inhibits cyclosporine metabolism and increases cyclosporine levels. Inhibition of cytochrome P450 3A4 (CYP3A4) may be partially responsible for this interaction (11784). An interaction between peppermint oil and cyclosporine has not been reported in humans.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, peppermint might increase the levels of CYP1A2 substrates.  Details In vitro and animal research shows that peppermint oil and peppermint leaf inhibit CYP1A2 (12479,12734). However, in clinical research, peppermint tea did not significantly affect the metabolism of caffeine, a CYP1A2 substrate. It is possible that the 6-day duration of treatment may have been too short to identify a difference (96359).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint might increase the levels of CYP2C19 substrates.  Details In vitro research shows that peppermint oil inhibits CYP2C19 (12479). So far, this interaction 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, peppermint might increase the levels of CYP2C9 substrates.  Details In vitro research shows that peppermint oil inhibits CYP2C9 (12479). So far, this interaction 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 Theoretically, peppermint might increase the levels of CYP3A4 substrates.  Details Clinical research in healthy volunteers shows that a single dose of peppermint oil 600 mg inhibits CYP3A4 enzymes and increases the AUC of felodipine, a CYP3A4 substrate (11783). However, in vitro research suggests that peppermint oil only inhibits CYP3A4 at very high concentrations (12479).

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General ...Orally, diluted eucalyptus oil is generally well tolerated, but the undiluted oil can cause toxicity.
Most Common Adverse Effects:
Orally: Diarrhea, nausea, vomiting.
Topically: Burning, itching, redness, stinging.
Serious Adverse Effects (Rare):
Orally: Signs of toxicity can occur with the undiluted oil at doses as low as 1 mL and include central nervous system depression, shallow respiration, rapid pulse, apnea, coma, and death.
Topically: Prolonged exposure or large amounts of eucalyptus oil can cause agitation, ataxia, drowsiness, muscle weakness, seizures, and slurred speech. The risk of toxicity may be greater in children.
Inhalation (as aromatherapy): Seizures.

Cardiovascular ...Orally, one case of premature ventricular contractions has been reported in a previously healthy 29-year-old male who ingested approximately one ounce of eucalyptus oil (48983).

Dermatologic ...Topically, eucalyptus pollen, leaves, oil, and the constituent eucalyptol can cause contact dermatitis in sensitive people (13303,48931,92856,92858,92859,98497). In some cases, symptoms respond to treatment with topical corticosteroids and tacrolimus (92856). In one case report, transient local redness, burning, and irritation was reported in a 4-year-old child who was bathed in water containing eucalyptus oil. The symptoms resolved within one hour of rinsing the skin with clear water (48983). In a clinical study, treatment with a combination of eucalyptus oil and lemon tea tree oil caused burning, redness, itching, or stinging in up to 20% of the patients. Stinging usually resolved within 10 minutes of application and redness within 30 minutes (19188,98492).

Gastrointestinal ...Orally, eucalyptus oil can cause nausea, vomiting, and diarrhea (48983,48993,48995). Abdominal pain has been reported in a trial of the eucalyptus constituent eucalyptol for inflammatory bowel disease (IBD) (48936).

Immunologic ...A case of IgE-mediated exacerbation of asthma and rhinitis symptoms has been reported in a patient who consumed eucalyptus. Similar worsening of symptoms occurred when the patient inhaled eucalyptus pollen (48957).
Occupational exposure to eucalyptus may cause allergic dermatitis (98497).

Neurologic/CNS ...Orally, eucalyptus oil can cause central nervous system depression, coma, and status epilepticus (12867,48946,48983).
Topically, orally, and by inhalation, eucalyptus oil has been associated with seizures. A systematic review describes the characteristics of 49 children and 61 adults with seizures associated with various routes of administration. Patients with no seizure history were classified as a eucalyptus oil-induced seizure (EOIS), while patients with a history of seizure or susceptibility to seizure were defined as a eucalyptus oil-provoked seizure (EOPS). In EOIS cases, topical use was reported in 74%, inhalation in 22.5%, and ingestion in 3.5%; for EOPS cases, topical use was reported in 79%, inhalation in 16%, and ingestion in 5%. Generalized tonic-clonic seizures are the most prominent type of seizure in EOIS cases (96%). Among EOPS patients, 37% had focal onset motor seizures with impaired awareness, 24% had focal onset aware motor seizures, 13% had focal to bilateral tonic-clonic seizures, and 26% had generalized onset tonic-clonic seizures (107494). One prospective observational study that was included in this systematic review provided additional details on eucalyptus-induced seizures. This study included 18 reports of EOIS and 28 reports of EOPS in adults and children after topical or inhaled use of eucalyptus oil, either alone or in combination with camphor. The time to seizure onset was 0.5-48 hours after topical application, 2-30 minutes after inhalation, and 0.5-6 hours after ingestion. (105028).
One prospective observational study and one case series have described 20 case reports of seizures occurring in children after ingestion of eucalyptus oil. Most of these seizures are generalized tonic-clonic in nature, occur 15-30 minutes after exposure, and do not reoccur following the discontinuation of eucalyptus oil. Seizures have been reported with both overdoses and therapeutic doses (107493,107495) and include cases of both EOIS and EOPS (107495). Additionally, children appear more likely to require intensive care and mechanical ventilation when compared with adult cases (107494).
A case of fever and headache has been reported in a patient who routinely applied a teaspoon of gel containing eucalyptus extract in his throat or nose to treat sore throat or rhinitis (48946).

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General ...Orally, topically, or rectally, peppermint oil is generally well tolerated. Inhaled, peppermint oil seems to be well tolerated. Intranasally, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted. Orally, peppermint leaf seems to be well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, anal burning, belching, diarrhea, dry mouth, heartburn, nausea, and vomiting.
Topically: Burning, dermatitis, irritation, and redness.

Dermatologic ...Topically, peppermint oil can cause skin irritation, burning, erythema, and contact dermatitis (3802,11781,31528,43338,68473,68457,68509,96361,96362). Also, a case of severe mucosal injury has been reported for a patient who misused an undiluted over the counter mouthwash that contained peppermint and arnica oil in 70% alcohol (19106).
In large amounts, peppermint oil may cause chemical burns when used topically or orally. A case of multiple burns in the oral cavity and pharynx, along with edema of the lips, tongue, uvula, and soft palate, has been reported for a 49-year-old female who ingested 40 drops of pure peppermint oil. Following treatment with intravenous steroids and antibiotics, the patient's symptoms resolved over the course of 2 weeks (68432). Also, a case of chemical burns on the skin and skin necrosis has been reported for a 35-year-old male who spilled undiluted peppermint oil on a previous skin graft (68572). Oral peppermint oil has also been associated with burning mouth syndrome and chronic mouth ulceration in people with contact sensitivity to peppermint (6743). Also, excessive consumption of mint candies containing peppermint oil has been linked to cases of stomatitis (13114).

Gastrointestinal ...Orally, peppermint oil can cause heartburn, nausea and vomiting, anal or perianal burning, abdominal pain, belching, dry mouth, diarrhea, and increased appetite (3803,6740,6741,6742,10075,11779,11789,17682,68497,68514)(68532,68544,96344,96360,102602,104219,107955). Enteric-coated capsules might help to reduce the incidence of heartburn (3802,4469,6740,11777). However, in one clinical study, a specific enteric-coated formulation of peppermint oil (Pepogest; Nature's Way) taken as 180 mg three times daily was associated with a higher rate of adverse effects when compared with placebo (48% versus 31%, respectively). Specifically, of the patients consuming this product, 11% experienced belching and 26% experienced heartburn, compared to 2% and 12%, respectively, in the placebo group (107955). A meta-analysis of eight small clinical studies in patients with irritable bowel syndrome shows that taking enteric-coated formulations of peppermint oil increases the risk of gastroesophageal reflux symptoms by 67% when compared with a control group (109980). Enteric-coated capsules can also cause anal burning in people with reduced bowel transit time (11782,11789).

Genitourinary ...Orally, a sensitive urethra has been reported rarely (102602).

Hepatic ...One case of hepatocellular liver injury has been reported following the oral use of peppermint. Symptoms included elevated liver enzymes, fatigue, jaundice, dark urine, and signs of hypersensitivity. Details on the dosage and type of peppermint consumed were unavailable (96358).

Immunologic ...One case of IgE-mediated anaphylaxis, characterized by sudden onset of lip and tongue swelling, tightness of throat, and shortness of breath, has been reported in a 69-year-old male who consumed peppermint candy (89479). An allergic reaction after use of peppermint oil in combination with caraway oil has been reported in a patient with a history of bronchial asthma (96344). It is not clear if this reaction occurred in response to the peppermint or caraway components.

Neurologic/CNS ...Orally, headache has been reported rarely (102602).

Ocular/Otic ...Orally, peppermint has been reported to cause blurry vision (3803).

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