Efficacy and safety of a low-dose 24-day combined oral contraceptive containing 20 micrograms ethinylestradiol and 3 mg drospirenone.

The aim of this open-label, multicenter, noncomparative study was to determine the efficacy, safety and bleeding profile of a new low-dose, monophasic combined oral contraceptive containing 20 micrograms ethinylestradiol and 3 mg drospirenone administered daily for 24 days followed by a 4-day hormone-free interval. Contraceptive efficacy was analyzed for 1018 women completing 11,140 treatment cycles. Eleven pregnancies occurred, giving a Pearl Index (PI) of 1.29 (upper limit of the 95% confidence interval [CI], 2.30); of these pregnancies, five were considered due to method failure, giving an adjusted PI of 0.72 (upper limit of the 95% CI, 1.69). A total of 7 (0.7%) women discontinued study medication because of irregular bleeding, suggesting a favorable bleeding profile. Overall, the treatment was well tolerated with an excellent safety profile. The majority of women (86%) stated that they were satisfied or very satisfied with the treatment and over 70% of women would have continued with the study medication.