title: Clinical experience with implant contraception.
abstract: Subdermal implants of polysiloxane (Silastic) capsules containing a number of synthetic progestagens have been studied in clinical trials to determine their contraceptive effectiveness and acceptability. The steroids studied include norgestrienone (R2010), gestrigone (R2323), megestrol acetate, d-norgestrel, norethindrone, ST-1435, lynestrenol and R-1364. With some of these steroids, studies have been undertaken with a varying number of implanted capsules. The estimated duration of use varies from 6 months to 6 years depending on dose and release rate of the individual steroid. The results of these studies involving about 5000 women in 8 years, indicate in general a high rate of effectiveness, as well as acceptability. Continuation rates at one year were generally 80% or greater. Abnormal bleeding patterns are the major disadvantage. Studies with implatns containing a combination of estrogen and progestogen are being undertaken in an attempt to improve the bleeding pattern.
mesh_terms: D003271:Contraceptive Agents, Female / Q000494:pharmacology*; D004343:Drug Implants; D005260:Female; D006801:Humans; D008234:Lynestrenol / Q000494:pharmacology; D008535:Megestrol / Q000494:pharmacology; D008598:Menstruation / Q000187:drug effects; D009640:Norethindrone / Q000494:pharmacology; D009644:Norgestrel / Q000494:pharmacology; D009645:Norgestrienone / Q000494:pharmacology; D009653:Norprogesterones / Q000494:pharmacology; D012826:Silicone Elastomers
chemical_list: D003271:Contraceptive Agents, Female; D004343:Drug Implants; D009653:Norprogesterones; D012826:Silicone Elastomers; D009644:Norgestrel; D009645:Norgestrienone; D008535:Megestrol; D008234:Lynestrenol; D009640:Norethindrone