Reduction by naproxen of excessive menstrual bleeding in women using intrauterine devices

Thirty-four patients using intrauterine contraceptive devices and experiencing excessive menstrual bleeding (more than 80 ml average loss for 2 cycles) were treated with the prostaglandin synthetase inhibitor naproxen. The trial was conducted according to a double-blind placebo-controlled crossover design. Each patient received 2 of 3 treatments: naproxen in high dose (1250 mg/day for 5 days), naproxen in low dose (500-mg loading dose, than 750 mg/day for 5 days), or placebo. Each treatment was taken during 2 consecutive menstruations. When all data were pooled, statistically significant reduction in menstrual bleeding was found with both high- and low-dose naproxen treatment compared with placebo therapy (P < .002). Low- and high-dose naproxen reduced menstrual blood loss by 22% and 32%, respectively, whereas the change with placebo was minimal. Although the dose had no significant effect on mean menstrual loss, the number of treatment cycles in which menstrual blood loss was reduced by 50% as compared with pretreatment cycles strongly suggested a dose response. In almost 60% of naproxen-treated cycles, mean menstrual blood loss was less than 80 ml, whereas during placebo-treated cycles the distribution of menstrual loss was similar to that of control cycles.