Shi Y E, Zheng S H, Zhu Y H, He C H, Yu P P, Fotherby K
Institute of Planned Parenthood Research, Shanghai, People's Republic of China.
Contraception. 1988 Apr;37(4):359-69. doi: 10.1016/0010-7824(88)90113-8.
The pharmacokinetics and pharmacodynamics of levonorgestrel (LNG) were studied in six women given 0.75 mg LNG orally for seven days during the periovulatory phase of the menstrual cycle. Steady-state concentrations of LNG were reached within three days and serum LNG concentrations at various times on day 7 were generally lower than on day 1, presumably due to a reduced serum level of SHBG. On day 7 the volume of distribution was significantly increased and Co significantly decreased and both the clearance and elimination half-life were higher on day 7 than on day 1. Half-lives varied from 5.6 to 25.1 hours. The day-to-day intra-subject variations in serum LNG concentrations ranged from 23% to 80%. Serum concentrations of pituitary and ovarian hormones suggested that ovulation was not inhibited in four of the six subjects and was delayed in the remaining two. No significant changes in serum prolactin levels were observed.
在月经周期的排卵期，对6名女性口服0.75毫克左炔诺孕酮（LNG），连续服用7天，研究了左炔诺孕酮（LNG）的药代动力学和药效学。3天内达到LNG稳态浓度，第7天不同时间的血清LNG浓度通常低于第1天，推测是由于SHBG血清水平降低所致。第7天分布容积显著增加，血药浓度显著降低，清除率和消除半衰期在第7天均高于第1天。半衰期为5.6至25.1小时。受试者血清LNG浓度的日内个体差异为23%至80%。垂体和卵巢激素的血清浓度表明，6名受试者中有4名排卵未受抑制，其余2名排卵延迟。未观察到血清催乳素水平有显著变化。
