A double-blind placebo-controlled crossover study of mebeverine and mefenamic acid in the treatment of primary dysmenorrhoea.
OBJECTIVE: i) To compare the efficacy of mebeverine, mefenamic acid and placebo in relieving the symptoms of primary dysmenorrhoea. ii) To compare the incidence of concurrent effects during treatment with mebeverine, mefenamic acid and placebo. DESIGN: Double-blind, prospectively randomised, three-way crossover study of mebeverine, mefenamic acid and placebo during three consecutive menstrual cycles. SETTING: University health centres in the UK. PATIENTS: Sixty-four females suffering from primary dysmenorrhoea who experienced pain during every menstrual cycle. INTERVENTION: Dosage was two capsules, three times daily, of mebeverine, mefenamic acid or placebo. Each mebeverine capsule contained 135 mg mebeverine hydrochloride, and each mefenamic acid capsule contained 250 mg mefenamic acid. Paracetamol (up to 2 x 500 mg) was permitted, if required, as rescue analgesia. MEASUREMENTS AND RESULTS: Details of pain severity, nausea, abdominal bloating and disruption to daily activities were recorded by means of clinician assessments and patient diaries. Patients indicated their treatment preference after three cycles. Mebeverine and mefenamic acid were superior to placebo in reducing pain severity (p less than 0.01 and p less than 0.02 respectively), and mefenamic acid reduced the level of disruption to normal activities (p less than 0.01). The number of concurrent effects reported was five during treatment with mefenamic acid and one each during treatment with placebo and mebeverine. CONCLUSIONS: Mebeverine and mefenamic acid are effective in relieving symptoms of dysmenorrhoea.