RESUMO
Persistent and/or unpredictable bleeding is a common reason for discontinuation of hormonal contraceptive methods. An open-label, nonrandomized, parallel, controlled study compared the efficacy, safety, and cycle control of the new, highly efficacious monthly injectable contraceptive containing 25 mg medroxyprogesterone acetate (MPA) and 5 mg estradiol cypionate (E(2)C) (MPA/E(2)C) (Lunelle Monthly Contraceptive Injection) with that of the frequently used norethindrone 0.5, 0.75, 1.0 mg/0.035 mg ethinyl estradiol (NET/EE) triphasic oral contraceptive (Ortho-Novum 7/7/7). This report directly compares the bleeding patterns of women on MPA/E(2)C to those of women on NET/EE and untreated women. Overall, breakthrough bleeding occurred less frequently in women using MPA/E(2)C than in women using NET/EE (p < or =0.01). However, more women using MPA/E(2)C experienced amenorrhea/missed periods than those on NET/EE (p < or =0.01). In addition, the percentage of women experiencing breakthrough bleeding or amenorrhea while using other oral contraceptives is compared to that of women using MPA/E(2)C. A rapidly reversible method, MPA/E(2)C, combines the high contraceptive efficacy of surgical sterilization with the convenience of monthly administration. These data suggest that, for a large proportion of women, MPA/E(2)C offers predictability in bleeding patterns comparable to or greater than that experienced by ovulatory untreated women or those using combination oral contraceptives.