New once‐a‐month injectable contraceptives, with particular reference to Cyclofem®/Cyclo‐ProveraTM

Abstract

Once‐a‐month injectable contraceptives containing a progestogen and an estrogen have been developed that disrupt vaginal bleeding patterns less than the widely used progestogen‐only preparations. Pharmacokinetic studies were undertaken of dosages and ratios of the progestogens and the respective estrogens. In Phase III clinical trials, annual pregnancy rates were below 0.4% for Mesigyna® (norethisterone enanthate/estradiol valerate, Schering AG, Berlin, Germany) and below 0.2% for Cyclofem® (MPA/E2C) (medroxyprogesterone acetate/estradiol cypionate, Aplicaciones Farmaceuticas, SA, Mexico and PT Tunggal, Indonesia). More than two‐thirds of women had predictable, regular cycles, and discontinuation due to bleeding‐related problems occurred less than half as often as with progestogen‐only injectables. With MPA/E2C, return to fertility is similar to that observed with other hormonal or intrauterine methods, and both products have little effect on lipids or hemostasis. Introductory trials of MPA/E2C in 12 000 women with 100 000 woman‐months of experience confirmed the high efficacy of the product in routine use. The use of Cyclofem in a non‐reusable injection device, Uniject® (Becton Dickinson, Franklin Lakes, NJ) is discussed. Once‐a‐month hormonal contraceptives have been shown to provide a safe contraceptive option for all women and an alternative for women who wish to use injectable formulations that cause less disruption in vaginal bleeding and minimal side effects.