长期使用Norplant妇女的LNG血药水平

Plasma Levels of Levonorgestrel in Nor-plant Implant Users,

对10例埋植Norplant(左旋18-甲基炔诺酮)的妇女作了五年的血药水平和释药速率及药物清除等药代动力学观察。研究结果显示埋植Norplant后24小时的血药水平是稳态血药水平的7倍左右,足以达到避孕的有效浓度。埋植Norplant后各时期的平均血药水平基本恒定,用药五年时的平均血药水平比用药早期略低;释药速率结果与血药浓度的变化趋势相似。取出埋植剂后,消除半衰期为27.94hr,血药降至小于100pmol/L的时间是91.13(78.19～106.22)小时,廓清率为151.64d/L。

The pharmacokinetics of Norplant were studied in ten Chinese volunteers. The plasma level of LNG in each Norplant user has been measured by RIA. After 24 hours of the insertion of the implants, the effective plasma level was reached 5. 52 nmol/L. It was 2. 25 nmol/L to measure the average level in the first years,was 1. 42 nmol/L in the second years, was 1.67hmol/L in the third years,was 0. 86 nmol/L in the fourth years, was 0.72nmol/L in the fifth years. The elimination T1/2 was 27. 94 hours and the CL was 151. 64 d/L. The time of LNG concentration dropped to minus 100 nmol/L was 91. 13 hours. The amount of LNG released from implants was 73. 64μg per 24 hours during the 101-400 days. During the 1-5 years release rates of LNG was 42. 6ug per 24 hours.