Efficacy and Safety of Peppermint Oil in a Randomized, Double-Blind Trial of Patients With Irritable Bowel Syndrome

Gastroenterology. 2020 Jan;158(1):123-136. doi: 10.1053/j.gastro.2019.08.026. Epub 2019 Aug 27.

Abstract

Background & aims: Peppermint oil is frequently used to treat irritable bowel syndrome (IBS), despite a lack of evidence for efficacy from high-quality controlled trials. We studied the efficacy and safety of small-intestinal-release peppermint oil in patients with IBS and explored the effects of targeted ileocolonic-release peppermint oil.

Methods: We performed a double-blind trial of 190 patients with IBS (according to Rome IV criteria) at 4 hospitals in The Netherlands from August 2016 through March 2018; 189 patients were included in the intent-to-treat analysis (mean age, 34.0 years; 77.8% female; 57.7% in primary care), and 178 completed the study. Patients were randomly assigned to groups given 182 mg small-intestinal-release peppermint oil, 182 mg ileocolonic-release peppermint oil, or placebo for 8 weeks. The primary endpoint was abdominal pain response, as defined by the US Food and Drug Administration: at least a 30% decrease in the weekly average of worst daily abdominal pain compared with baseline in at least 4 weeks. The co-primary endpoint was overall relief of IBS symptoms, as defined by the European Medicines Agency. Secondary endpoints included abdominal pain, discomfort, symptom severity, and adverse events.

Results: Abdominal pain response did not differ significantly between the peppermint oil and placebo groups: 29 of 62 patients in the small-intestinal-release peppermint oil group had a response (46.8%, P = .170 vs placebo), 26 of 63 patients in the ileocolonic-release peppermint oil group had a response (41.3%, P = .385 vs placebo), and 22 of 64 patients in the placebo group had a response (34.4%). We did not find differences among the groups in overall relief (9.7%, P = .317 and 1.6%, P = .351 vs 4.7% for placebo). The small intestinal peppermint oil did, however, produce greater improvements than placebo in secondary outcomes of abdominal pain (P = .016), discomfort (P = .020), and IBS severity (P = .020). Adverse events, although mild, were more common in both peppermint oil groups (P < .005).

Conclusions: In a randomized trial of patients with IBS, we found that neither small-intestinal-release nor ileocolonic-release peppermint oil (8 weeks) produced statistically significant reductions in abdominal pain response or overall symptom relief, when using US Food and Drug Administration/European Medicines Agency recommended endpoints. The small-intestinal-release peppermint oil did, however, significantly reduce abdominal pain, discomfort, and IBS severity. These findings do not support further development of ileocolonic-release peppermint oil for treatment of IBS. Clinicaltrials.gov, Number: NCT02716285.

Keywords: Functional Gastrointestinal Disorder; PERSUADE Study; RCT; Treatment.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdominal Pain / diagnosis
  • Abdominal Pain / drug therapy*
  • Abdominal Pain / etiology
  • Administration, Oral
  • Adolescent
  • Adult
  • Aged
  • Analgesics / administration & dosage*
  • Analgesics / adverse effects
  • Capsules
  • Double-Blind Method
  • Female
  • Humans
  • Intestinal Mucosa / drug effects
  • Irritable Bowel Syndrome / complications
  • Irritable Bowel Syndrome / diagnosis
  • Irritable Bowel Syndrome / drug therapy*
  • Male
  • Middle Aged
  • Netherlands
  • Pain Measurement
  • Plant Oils / administration & dosage*
  • Severity of Illness Index
  • Treatment Outcome
  • Young Adult

Substances

  • Analgesics
  • Capsules
  • Plant Oils
  • peppermint oil

Associated data

  • ClinicalTrials.gov/NCT02716285