The effect of mefenamic acid and naproxen on heavy menstrual bleeding: A placebo-controlled study

Abstract

Background. Heavy menstrual bleeding is a common complaint. Various therapeutic approaches have been suggested.

Aim. To compare the efficacy of mefenamic acid and naproxen in reducing heavy menstrual bleeding.

Methods. Women referred to an outpatient centre for treatment of heavy menstrual bleeding were recruited. Participants who met the inclusion criteria were evaluated for 6 menstrual cycles. During 3 control cycles they recorded the amount of their bleeding on the Pictorial Blood Assessment Chart to confirm that their menstrual bleeding was heavy. One hundred and twenty participants were then randomly assigned to receive mefenamic acid, naproxen or placebo, and asked to fill in the same questionnaires during 3 intervention cycles. The data were analysed using SPSS version 15 for Windows.

Results. Participants receiving mefenamic acid experienced a marked decrease in bleeding during the 3 months of intervention, an initial sharp decrease being followed by a further lesser decrease (p<0.05 within group). Bleeding lessened dramatically in the first month of the intervention in participants receiving naproxen, and dropped still further in the second and third months (p<0.05 within group). In the placebo group there were slight changes in bleeding during the intervention (p>0.05 within group). However, the total decrease in bleeding was greatest in the naproxen arm, and the differences between the groups were statistically significant (p<0.05 between groups).

Conclusion. All three interventions had positive effects on the mean amount of bleeding, although naproxen was more effective than mefenamic acid and much more effective than placebo.