Drospirenone-only oral contraceptive: results from a multicenter noncomparative trial of efficacy, safety and tolerability.

OBJECTIVES

This study was performed to assess the contraceptive efficacy of the drospirenone (DRSP)-only pill and to provide information regarding its safety and cycle-control profile.

STUDY

DESIGN

This prospective, multicenter, noncomparative study was conducted at 41 European sites in healthy women at risk of pregnancy, aged 18 to 45 years. The study medication was DRSP 4.0mg daily for 24 days followed by a placebo for 4 days (DRSP 4 mg 24/4, Exeltis, Spain) for thirteen 28-day treatment cycles. The primary efficacy endpoint was the overall Pearl Index (PI). Bleeding patterns, changes in vital signs and changes in laboratory values were also analyzed.

RESULTS

A total of 713 participants with 7638 DRSP treatment cycles were analyzed. The overall PI was 0.51 (95% confidence interval, 0.1053-1.4922). The proportion of participants with any bleeding decreased from 72.7% in Cycle 1 to 40% in Cycle 6 and 32.1% in Cycle 13. Unscheduled bleeding decreased from 49.1% in Cycle 1 to 27.8% in Cycle 6 and to 22.8% in Cycle 13. Prolonged bleeding was reported by 6.5% during Cycles 2 to 4 decreasing to 4.2% during Cycles 11 to 13. There were no reports of deep vein thrombosis, pulmonary embolism or hyperkalemia. No relevant changes were observed for laboratory parameters, body weight, body mass index, blood pressure or heart rate. Study drug acceptability was considered as "excellent/good" by over 82% of subjects.

CONCLUSION

This new DRSP-only oral contraceptive provides clinical contraceptive efficacy similar to that of the currently marketed Combination estrogen plus progestin Oral Contraceptive, with a good safety profile, and favorable cycle control.

IMPLICATIONS: A novel 4-mg DRSP-only pill taken daily for 24 days followed by a placebo for 4 days demonstrated contraceptive efficacy similar to that of currently marketed Combination estrogen plus progestin Oral Contraceptive, with a good safety profile, and favorable cycle control.