In-vivo response of the human uterus to orciprenaline in early labour.

The effect of orciprenaline on uterine activity in 10 women in early induced labour at term with intact membranes was studied. Nine had uterine contractions in response to intravenous oxytocin and one to prostaglandin E(2). The inhibition of uterine contractility was dose-dependent. The effective dose varied between 10 and 20 mug/minute. Tachyphylaxis was not observed. The only significant effects noted in the mother were tachycardia and increased pulse pressure and in the fetus a smaller increase in heart rate.