Objective: To assess the contraceptive reliability, cycle control and tolerance of a new monophasic oral contraceptive (Yasmin) containing 30 microg ethinylestradiol and 3 mg drospirenone and compare it with a preparation containing an equal dose of ethinylestradiol combined with 150 microg desogestrel (Marvelon).
Methods: A multicenter, open-label, randomized study was carried out in 26 European centers. Contraceptive efficacy, cycle control and tolerance (including body weight, blood pressure and heart rate) were assessed over 26 cycles, plus a 3-month follow-up period.
Results: Of 900 women who were randomized, 887 started treatment and 627 completed the 26 cycles plus follow-up (310 in the ethinylestradiol/drospirenone group and 317 in the ethinylestradiol/desogestrel group). Both study preparations were found to be effective with regard to contraceptive reliability and cycle control was good. There were six pregnancies (three in each group), but none were considered to have been the result of method failures. The subjective and objective tolerances were good in both groups. A statistically significant difference was found in body weight changes between the two groups. While there was an increase in mean body weight in the ethinylestradiol/desogestrel group from cycle 5 onward, the mean body weight per cycle in the ethinylestradiol/drospirenone group was slightly below the baseline value throughout the study. The incidence ofpremenstrual symptoms was higher in the ethinylestradiol/drospirenone group than in the ethinylestradiol/desogestrel group during the 6 months prior to the study, but lower during treatment. The rates ofdysmenorrhea were identical under both treatments but the symptoms were more often mild and less often severe in the ethinylestradiol/drospirenone group.
Conclusion: The combination of 30 microg ethinylestradiol combined with 3 mg drospirenone provides effective oral contraception and good cycle control, and is well tolerated. Ethinylestradiol/drospirenone had a more favorable effect on body weight than ethinylestradiol/desogestrel, with the mean body weight remaining lower than baseline for the majority of the women.