Shoupe D, Mishell D R
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles 90033.
Am J Obstet Gynecol. 1989 May;160(5 Pt 2):1286-92. doi: 10.1016/s0002-9378(89)80014-6.
Norplant offers long-term contraception through the use of subdermal capsules filled with levonorgestrel. The six capsules are implanted in the inside part of the upper arm. The levonorgestrel is released from the capsules gradually, providing contraception for about 5 years. The primary mechanism of action of Norplant is suppression of ovulation. Studies have shown a pregnancy rate of 0.6/100 woman-years after 1 year and a cumulative rate of 1.5/100 woman-years at 5 years. Principal side effects are irregular menstrual bleeding and headaches. No changes in carbohydrate metabolism, blood coagulation, or liver function have been reported. Lipid levels have decreased 5% to 15%. After removal of Norplant, fertility returns rapidly, and there have been no adverse effects on infants. Norplant is currently approved in 12 countries; clinical trials are being conducted in 37 countries.
诺普兰通过使用填充左炔诺孕酮的皮下胶囊来提供长效避孕作用。这六颗胶囊被植入上臂内侧。左炔诺孕酮从胶囊中逐渐释放，可提供约5年的避孕效果。诺普兰的主要作用机制是抑制排卵。研究表明，1年后每100名妇女年的妊娠率为0.6，5年后累积妊娠率为每100名妇女年1.5。主要副作用是月经出血不规律和头痛。未报告碳水化合物代谢、血液凝固或肝功能有变化。血脂水平下降了5%至15%。取出诺普兰后，生育能力迅速恢复，且对婴儿无不良影响。诺普兰目前在12个国家获得批准；37个国家正在进行临床试验。
