【摘要】 对本室设计制备的左炔诺孕酮(Levonorgestrel,LNG)阴道避孕环(以20μg/d速度恒速释药)的体内血药浓度和消除动力学进行测定。5名健康妇女于放入此环8d中及环取出后72h内的不同时间取血,用放射免疫法测定血药浓度。结果发现放环后药物的吸收和消除特性与国外报道的相似,体内血药浓度变化与其体外释药规律相符。环放入阴道后,药物吸收1h内即达稳态,8h左右出现一个血药浓度峰,以后血药浓度趋于平稳。环取出后的药物消除分二相。取环后24h内,半衰期为14.3h;24～72h内,平均半衰期为61.9h。更多还原

【Abstract】 The pharmacokinetio effects of vaginal devices releasing levonorgestrel (LNG) at a constant rate (in vitro release: approximately 20μg/d) were studied in 5 normally menstruating women. Blood samples were drawn at definite times during 8 days of exposure to the ring and during 72 hours following its removal. The levels of LNG were obtained by radioimmunoassay.Following insertion of the devices, the levels of LNG rose very rapidly and reached a "plateau" within 1 hour. This was followed by a "burst" period of a few hours, after which the levels remained stable. In 24 hours following removal of the device the half-life was 14.3 hours, in 24 to 72 hours after removal of the ring the half-life was 61.9 hours.更多还原