Antiprogestin drugs: research and clinical use in Sweden

Abstract

The Swedish experience indicates that the combination of RU 486 and vaginal or intramuscular administration of different prostaglandin analogues such as Cervagem, Sulprostone, and 15- methyl PGF2 alpha is a highly effective and safe non-surgical method to terminate early pregnancy. The combined treatment may also be used during the second trimester. In mid- and late second trimester abortion this procedure represents a simple, non-invasive, highly effective method. There are several possibilities by which RU 486 can be used as a contraceptive. We have shown that post-ovulatory administration of RU 486 will effectively inhibit implantation. If the preliminary results are confirmed, treatment with RU 486 once a month on day LH+2 may be an attractive alternative to present contraceptive technology.

PIP: The seminal research done in Sweden that established the prostaglandin enhancement of RU-486 as a medical early abortion method, continuing research on this method, and newer applications such as second trimester termination and monthly contraception with RU-486, are briefly reviewed. The author's research was fundamental in describing the increased sensitivity of the myometrium to prostaglandins by RU-496 given in early pregnancy. Now, in France, either in Sulprostone or vaginal Gemeprost are given 48 hours after RU-486 to effect complete abortion with a comparable complication rate to vacuum aspiration. New research in collaboration with the World Health Organization has shown that doses of RU-486 can be reduced to as low as 400 or 200 mg, or possible even 50 mg, and still yield complete abortion in 97% of women. Swedish research suggested that 75% of women who choose abortion make their decision at the time of their missed menses, so the availability of a medical termination done at that time will not add to the number of abortions. Swedish women report that they appreciate the medical method, but do not consider taking the "abortion pill" a trivial matter. Ru-486 has been used for midtrimester abortion, and has been found to decrease the duration of labor and gastrointestinal side effects. Finally, preliminary work with RU-486 as a once-a-month 200 mg pill, taken 2 days after the luteinizing hormone surge, shown by a urine color test, has demonstrated effective contraception in 20 women for up to 12 months.