Mefenamic acid for dysmenorrhea

To the Editor.— Penny W. Budoff, MD (241:2713, 1979), has suggested that mefenamic acid, by virtue of its ability to inhibit prostaglandin activity, in addition to its ability to inhibit prostaglandin synthesis, may offer the advantage of allowing initiation of therapy for primary dysmenorrhea on the day of initial menstrual flow rather than beginning therapy one to two days before expected menses, as has been advocated for other inhibitors of prostaglandin synthesis (ie, naproxen, or indomethacin). This approach eliminates risk of exposing a fetus to these drugs if conception occurred during the cycle. Lundström1compared the pain-relieving effect of indomethacin and naproxen in regard to the day of the menstrual cycle on which treatment was started. Patients who received prostaglandin synthetase inhibitors one to five days before the onset of their menstrual flow were compared with those treated from the first day of bleeding. The overall results indicated that