A multicentred phase III comparative clinical trial of depot-medroxyprogesterone acetate given three-monthly at doses of 100mg or 150mg: 1. Contraceptive efficacy and side effects

Two dosages of depot-medroxyprogesterone acetate (DMPA), 100mg and 150mg given every 90 days, were compared in two groups of women with regard to effectiveness, reported complaints and reasons for discontinuation. A total of 1216 women were recruited into a seven-centre, multinational, randomized clinical trial. Follow-up was for a period of one year and resulted in a total of 5507 woman-months of experience of 100mg DMPA and 5429 woman-months of experience of the 150mg dose. The study showed little difference in efficacy and side effects between the two treatment groups. Two pregnancies occurred in women receiving 100mg DMPA giving a Pearl Index of 0.44 per 100 woman-years. None occurred in the 150mg group. There was no difference in the overall continuation rates between the two groups at one year, being 59.3% in the 100mg group and 58.8% in the 150mg group. Except for discontinuation of method use for amenorrhea, the rates of all medical and non-medical reasons given for discontinuation were comparable between the two treatment groups. Women's perception of lack of bleeding was reported as amenorrhea and resulted in discontinuation rates at 12 months for amenorrhea of 7.2% for women receiving 100mg of DMPA and 12.5% for those receiving the 150mg dose. Three centres, Alexandria, Karachi and Szeged, made the major contributions to this difference. © 1986.