Misoprostol alone for early abortion: an evaluation of seven potential regimens

A growing body of literature has shown that misoprostol alone could be effective for early medical abortion. We evaluated seven potential regimens in women up to 56 days of gestation in order to potentially identify an optimal regimen.

In phase I of the study, women requesting early abortion were randomized to one of three misoprostol regimens (4x400 microg po every 3 h, 2x800 microg po every 6 h, 1x600 pv microg); in phase II, women were randomized to one of two regimens (2x800 microg po every 3 h, 1x800 pv microg). In phase III, we consecutively tested two regimens (800 microg pv wetted with saline repeated after 24 h if intact gestational sac, 2x800 microg pv wetted with saline) to validate previously published results.

Although most women experienced some side effects, all regimens were tolerable and acceptable. Five of the seven regimens resulted in complete abortion rates of 60% or less. Only repeated doses of 800 microg pv misoprostol resulted in efficacy exceeding 60%.

Misoprostol-alone abortion regimens using oral misoprostol are too ineffective for clinical use or further investigation. Regimens with repeated dosing of misoprostol 800 microg pv warrant further study to find the optimal treatment protocol.