Progestin implants

Progestin implants for contraception are highly effective, safe, and the mo st convenient choice for many women. Progestin implants currently on the ma rket, preparing for launch, or under investigation are reviewed here. Their basic galenic and pharmacokinetic features, as well as their contraceptive effectiveness, are described. The first progestin-only contraceptive impla nt placed on the market was Norplant((R)), a multiunit system. Since then, several single- and double-rod implants have been developed, each using one of four different progestins: levonorgestrel, etonogestrel, Nestorone((R)) , and nomegestrol acetate. Jadelle((R)) is similar to Norplant but consists of only two, rather than six, Silastic rods to simplify insertion and remo val; nevertheless, levonorgesterel serum levels are identical, and performa nce is the same for both systems. The single implant systems reviewed here are: Implanon((R)) with a 3-year duration; Nestorone implants for breast fe eding and non-breast feeding women lasting up to 2 years; and Uniplant, whi ch is effective for 1 year. The advantages and disadvantages of progestin i mplants, the importance of counseling for increasing user satisfaction, and the future outlook for this contraceptive method are also discussed. (C) 2 000 Elsevier Science Inc. All rights reserved.