Abstract

PIP: 2 populations attending WHO centers, one in Sweden and one in India, participated in a comparative, pilot trial of 2 increasingly popular injectable progestin-only female contraceptives, Depo-Provera and Norigest. The purpose of the study was to assess the pharmacokinetic and pharmacodynamic properties of the 2 formulations (depot medroxyprogesterone acetate and norethisterone enanthate). Differences were found between Swedish women and Indian women in their reactions to the 2 drugs: 1) Norigest was detectable in blood samples a significantly shorter time after injection of the agent in Indian women than in Swedish women; this difference was not apparent with Depo-Provera. 2) Although there was no difference at the 2 centers in the time of ovulation return for subjects receiving Norigest, 0 of 4 Swedish women ovulated more than 156 days after Depo-Provera injection, whereas all 4 Indian women ovulated within 73 days of Depo-Provera injection; in the Swedish women, the levels of medroxyprogesterone were undetectable at time of return to ovulation, whereas Indian women had levels of .6 ng/ml when ovulation resumed. 3) In both cultures, Depo-Provera users had significantly more episodes of bleeding and spotting than Norigest users. This preliminary report emphasizes the variety of responses possible to injection of different contraceptive progestins among various populations and points to the need for further culturally comparative studies.