Peppermint Compared with Mefenamic Acid in Primary Dysmenorrhea
Reviewer: Dr. Tori Hudson, ND
Author: Masoumi S, Asi H, Poorolajal J, et al.
Reference: Evaluation of mint efficacy regarding dysmenorrhea in comparison with mefenamic acid: a double blinded randomized crossover study. Iran J Midwifery Res 2016;21(4):363-367
Design: This was a prospective, double-blinded, crossover study conducted in college women who had experienced primary dysmenorrhea. The young women were asked to take either mefenamic acid or peppermint oil starting from the first day of menses onset for 3 days. The study was conducted for 2 months in women ages 18-25 who already had primary dysmenorrhea. Group 1 received 3 peppermint oil capsules (Colpermin containing Peppermint Oil BP 0.2ml)) once a day for 3 days after menses started, followed by a period of washout in the next cycle. Then in the third menstruation, they were given 250 mg of mefenamic acid every 8 hours for the first 3 days. Group 2 received the same combination but in reverse order.
Participants: At entry, the study included 144 young university women, aged 18-25 who already had primary dysmenorrhea. In the end, 122 women were analyzed. The mean age was 20.99 years. The mean weight was 55.09 kg and 141.63 cm. Women were of similar age in each group, had similar number of days of menstruation, similar menarche and similar dysmenorrhea. Other inclusion criteria besides primary dysmenorrhea were regular menses, being single and between ages 18-25. Women were excluded if they had: an allergy to mint, cholecystitis, gastroesophageal reflux, severe liver disease, sensitivity to mefenamic acid, ulcers, kidney or liver disease, blood dyscrasia, asthma, diabetes mellitus, and extreme sensitivity to aspirin.
Primary outcome: Pain intensity was assessed through visual analog scale (VAS) and dysmenorrhea timing through COX menstrual symptom scale. The bleeding amount was measured using a chart. VAS and COX questionnaires were filled out in the beginning and at the end of each menses. If they took a sedative for pain, they were allowed to do this 1 hour after consuming the treatment capsule, but had to record the intensity and duration of their pain in the questionnaire before taking the sedative drugs.
Key findings: In the final count, 122 women were analyzed for results. The average pain intensity and duration of pain were signiticantly lower after the intake of both mefenamic acid and mint and there was no significant difference between the two. The average duration of pain was better with both treatments, and was slightly more reduced in the mefenamic acid group than the mint group. The average bleeding amount was significantly lower in the mefenamic acid group than in those taking the mint. Nausea and diarrhea were lower in the mint group than in the mefenamic acid group. Analgesic use was lower in the Mefenamic Acid group than in the peppermint group.
Practice Implications: Primary dysmenorrhea is associated with painful uterine contractions, and often also associated with nausea, vomiting and diarrhea. The pain is primarily due to the release of prostaglandin F2alpha in the menstrual fluid. The main conventional treatments are nonsteroidal anti-inflammatory drugs (NSAIDS), prostaglandin inhibitors and oral contraceptive pills. Mefenamic acid is a mild analgesic and fever reducing NSAID used for relief of more moderate pain with over the counter NSAIDS do not work sufficiently, are not well tolerated, or are contraindicated. Peppermint oil inhibits prostaglandin F2alpha and oxytocin and thus exerts an effect on the myometrial contractions. It also has some analgesic and anti-inflammatory effects. The menthol in the mint, is likely responsible for reducing vomiting and diarrhea.
Peppermint oil in the dosage utilized in this study should be considered comparable to mefenamic acid in reducing pain intensity, and similar to in reducing duration. In addition, the peppermint oil has the advantage of also reducing nausea/vomiting and diarrhea associated with the menstrual cramps. Mefenamic acid is a prescription and somewhat expensive medication, and can cause complications such as gastrointestinal bleeding, ulcers, flatulence, indigestion and stomach pain.