Efficacy, safety and cycle control of five oral contraceptive regimens containing norgestimate and ethinyl estradiol

This randomized, multicenter, parallel group study evaluated four new oral contraceptive regimens of norgestimate (NGM) and ethinyl estradiol (EE) relative to ORTHO TRI-CYCLEN® (NGM 180/215/250 μg/EE 35 μg). Healthy women (50/group) received three cycles of either ORTHO TRI-CYCLEN® Lo (NGM 180/215/250 μg/EE 25 μg), one of three cyclophasic regimens (NGM cycling 180-250 μg/EE 35 μg or 25 μg) or ORTHO TRI-CYCLEN. Among all five regimens, ovulation suppression, cycle control and safety were generally comparable. Presumed ovulation (serum progesterone levels ≥3 ng/mL during Days 19-21 of Cycle 3), occurred in 0/41 (0%) subjects on ORTHO TRI-CYCLEN Lo and 3/43 (7%) subjects on ORTHO TRI-CYCLEN. Breakthrough bleeding and/or spotting (BBS; % total cycles) was 17.2% for ORTHO TRI-CYCLEN Lo and 14.4% for ORTHO TRI-CYCLEN. The mean number of days of BBS/cycle for ORTHO TRI-CYCLEN Lo and ORTHO TRI-CYCLEN was 3.7 and 3.1, respectively, for those subjects with such bleeding. Thus, ORTHO TRI-CYCLEN Lo appears similar to ORTHO TRI-CYCLEN in inhibiting ovulation and providing cycle control.