Clinical Pharmacodynamies of Mffepristone （RU486） for Terminationof Early-Pregnancy

摘要

Twenty-four healthy female volunteers with amenorrhea for seven weeks or less,asking .for legal termination of pregnancy were recruited and divided into 4 groups (6each), The subjects were orally administered with RU486 of 50mg (Group I), 50mgQ12h×6 (Group Ⅱ ), 200mg (GroupⅢ) or 600mg (Group Ⅳ ). Vacuum aspiration( Group Ⅰ) or Methyl Carprost Suppository ( PG05 1.0mg) (Group Ⅱ-Ⅳ) was given 72h after the first dose followed by a 6-hour medical surveillance. Blood samples were collected on day 1-6, 8, 15, 43 to measure the serum levels of β-hCG, E2, P, PRL,ACTH, Cortisol. T3, T4 and TSH in eaeh subject. The results showed that no significant dose-effect relationship was observed in terms of clinical efficacy, vaginal bleeding or side effects, All four groups shared the same tendency of changes in serum levels of β-hCG, E2 and P, β-hCG levels increased by 50-100% (P<0. 01) 24h prior to treatment, and continued to increase following treatment umif the sac expulsion. E2 levels in each group remained higher than pre-treatment,values with the gradual decline in P levels, β-hCG, E2 and P decreased drastically after abortion, levels of β-hCG, E2, P on day 5 were only 35-60% (P< 0.01), 32-46%(P< 0,01) and 30-56% ( P< 0.01) of those on day 4 respectively. The mean PRL levels on day 2-4 in each group inereased obviously but dectined gradually following the sac expulsion. During treatment, the respective cortisol levels increased dramatically, the average levels of eortisot on day 2-4 were 30-40% (P< 0.05) in Group Ⅰ -Ⅲ and 60%( P< 0.01) in Group Ⅳ higher as compared with day 1 values, while deereased rapidly after termination of pregnancy as indicated that eortisot levels on day 5 were only 67-81% (P< 0.05) of those on day 4. The changes in ACTH, T3, T4, TSH levels were of no statistic significance ( P> 0.05). This study indicated that RU486 has no dose-effect relationship when used for interruption of early pregnancy and its main action site seems neither in ovary nor in villi. It has some effects on pituitary-adrenat axis, especially in large dosage, however, it has no obvious impact on pituitary-thyroid axis. It seems that the changes in PRL serum levels were directly due to the drug itself, its clinical significance should be further studied,