Abstract
48 patients in the first trimester of pregnancy received a single oral dose of placebo or enisoprost (prostaglandin E1 analogue): 10, 25, 50, 100, 200 or 400 μg. Uterine activity was recorded for 1 h before and for 4 h after administration of the study drug with a Millar microtransducer. There was a dose-related increase in mean resting and active pressure, but not in frequency of pressure cycles. At the highest dose used, namely 400 ug, all 6 subjects bled. Enisoprost dilated the cervix and any further dilatation required was easy to accomplish.