New once-a-month injectable contraceptives, with particular reference to Cyclofem/Cyclo-Provera.
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 12000 women with 100000 woman-months of experience confirmed the high efficacy of the product in routine use. The use of MPA/E2C 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.
Hall
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UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction, World Health Organization, Geneva, Switzerland.
D017326:Clinical Trials, Phase III as Topic; D003271:Contraceptive Agents, Female / Q000378:metabolism / Q000494:pharmacology / Q000600:supply & distribution; D003277:Contraceptives, Oral, Combined / Q000378:metabolism / Q000494:pharmacology / Q000600:supply & distribution; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D004353:Drug Evaluation, Preclinical; D004958:Estradiol / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology / Q000600:supply & distribution; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular / Q000295:instrumentation; D017258:Medroxyprogesterone Acetate / Q000378:metabolism / Q000494:pharmacology / Q000600:supply & distribution; D018579:Patient Selection; D011247:Pregnancy / Q000706:statistics & numerical data; D014944:World Health Organization
D003271:Contraceptive Agents, Female; D003277:Contraceptives, Oral, Combined; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D004958:Estradiol; C034528:CycloProvera; D017258:Medroxyprogesterone Acetate