Termination of early pregnancy using flexible, low-dose mifepristone-misoprostol regimens.

Background: Various regimens of mifepristone and misoprostol are used in medical abortion. We examined the effect of a change in protocol from a fixed mifepristone-misoprostol interval to a flexible one on the efficacy and uptake of medical abortion. In addition, risk factors of incomplete abortions were evaluated.

Changes in vaginal morphology, steroid receptor and natural antimicrobial content following treatment with low-dose mifepristone.

Background: We have previously shown that the antigestagen mifepristone is contraceptive when given in a daily dose of 5 mg, po. Epidemiological studies suggest that gestagen-only contraceptives may increase the risk of transmission of human immunodeficiency virus (HIV) due to effects on the vaginal defenses to infection. We investigate the effects of mifepristone on vaginal thickness, steroid receptor and natural antimicrobial content and pharmacokinetics of mifepristone.

Mifepristone may inhibit the midcycle gonadotropin surge at both ovarian and pituitary sites of action.

The ability of mifepristone to delay ovulation is thought to be based on the antigonadotropic effects of the drug. In the current work, late-follicular phase administration of mifepristone resulted in decrease in both circulating FSH and inhibin B, suggesting both central and ovarian sites of action.

Late follicular phase administration of mifepristone suppresses circulating leptin and FSH - mechanism(s) of action in emergency contraception?

Objective: Low dose mifepristone (RU486) is highly effective in emergency post-coital contraception (EC), although the mechanism(s) of action remains unclear. We studied the endocrine actions of 10 mg mifepristone administered orally as a single dose to eight healthy volunteers (aged 20-45 years) during the late follicular phase.

Methods: Serum levels of LH, FSH, oestradiol, progesterone, leptin, mifepristone, cortisol, and gluco-corticoid bioactivity (GBA) were measured before and 1, 2, 4 and 8 h after ingestion of mifepristone on cycle day 10 or 11 (study day 1), and follow-up was continued for 10 days.

Pharmacokinetics of 10 mg of mifepristone.

The results of several randomized studies have verified the efficacy of 10 mg mifepristone in emergency contraception. In the present study we characterized the pharmacokinetics of 10 mg mifepristone. Eight healthy female volunteers received a single oral dose of mifepristone on the day 10 or 11 of their menstrual cycle.