Naproxen sodium in menstrual migraine prophylaxis: a double-blind placebo controlled study. In this study, the efficacy of Naproxen sodium (Nxs) in the prophylaxis of Menstrual Migraine (MM) was tested, versus Placebo (PL). Forty women suffering from MM were admitted to a double-blind treatment protocol with Nxs 550 mg twice each day by mouth or Placebo (PL), for 3 months; in the next 3 months all the women were treated with the active drug in an open study. The headache intensity and duration, as well as the number of days of headache and the analgesic consumption, were significantly reduced with Nxs compared to PL. The efficacy of Nxs, shown also in improving premenstrual pain, and its good tolerability, support the use of this drug in the prophylactic therapy of MM. 