Distribution of oral nimesulide in female genital tissues

Nimesulide is a non-steroidal anti-inflammatory agent which has proved to be effective in reducing menstrual discomfort in dysmenorrhoeaic women. To determine the concentrations of this drug in the uterus (fundus, cervix), oviduct, and ovaries and to correlate these findings with plasma concentrations, a single oral dose of 100 mg nimesulide was administered 1 to 6 h before surgery to 12 women undergoing hysterectomy and salpingo-oophorectomy, mainly for fibroids. Tissue samples were taken, concentration of nimesulide measured by HPLC, and findings compared with plasma concentrations. One patient not undergoing treatment served as control. Nimesulide concentration in the tissues studied was highest 3 h after administration, as expected from the drug's pharmacokinetic profile. The highest tissue/plasma ratio (0.5) was also found at that time. Average tissue concentrations at 1, 2, 3, and 6 h after drug intake ranged from 0.3 to 1.8 micrograms g-1, and plasma concentrations from 2.6 to 4.1 micrograms ml-1. Nimesulide was evenly distributed in the tissues studied.