Action of metergoline in suppressing prolactin release induced by mechanical breast emptying.

Ten women were studied during the first post-partum week. Mechanical breast emptying with a breast pump for 30 min induced a marked increase in plasma prolactin (PRL) reaching a maximum 30 min after the beginning of stimulation. In all patients oral administration of the antiserotonin agent metergoline, 8 mg daily for two days, completely blocked any PRL secretion induced by breast stimulation. These results confirm the inhibitory effect of metergoline on PRL release.