Response to intermittent RU486 in women.

OBJECTIVE

To determine the effects of intermittent administration of the antiprogestin RU486 on ovarian function.

DESIGN

Three different regimens of RU486 were tested.

PARTICIPANTS

Nine healthy regularly menstruating volunteers protected by an intrauterine device or surgical sterilization.

INTERVENTIONS

Two groups of three women each received 10 mg or 50 mg RU486 at weekly intervals for 5 weeks. Another three women received 50 mg RU486 for 3 consecutive days at 10-day intervals for 80 days.

MAIN OUTCOME MEASURES

Serum E2, P and RU486 levels. Ovarian ultrasound (US) and serum LH and FSH in select subjects.

RESULTS

The predominant effect was partial inhibition of E2 secretion and suppressed P levels. During a total aggregate of 16 treatment months, there were seven episodes of elevated P levels; however, US did not always indicate the occurrence of normal ovulation.

CONCLUSION

Intermittent RU486 administration can interfere with normal follicular development and function, but its clinical application may require a more effective dose and/or timing of administration.