Inhibition of Puerperal Lactation by Metergoline: Interactions with Methylergobasine Maleate

Abstract

Metergoline, a prolactin (PRL) lowering drug, is used in the puerperal period to inhibit lactation. Methylergobasine maleate (MEM), widely employed in the puerperium to promote uterine contractions, has also been reported to decrease PRL release and to reduce lactation. To evaluate the possible interactions of the two drugs, groups of 6–11 puerperae each received no treatment, metergoline alone (8 or 12 mg/day for 5 days), MEM alone (0.2 mg i.v. at delivery followed by 0.5 mg/day p.o. for 5 days) and metergoline plus MEM. Metergoline fully prevented lactation and significantly reduced PRL release, the higher dose inducing effects faster. MEM was without effect on PRL release and lactation, and did not modify the effect of metergoline.

Use of Bromocriptine to Prevent Puerperal Lactation During Neuroleptic Treatment of Chronic Schizophrenia

“…This outcome may have been due to the two drugs achieving a suitable dopaminergic balance; both at the level of the lactotrophs and at the level of the mesolimbic and mesocortical systems. Additionally, it should be noted that, when used to support postgestational involution of the uterus for aperiod of nine days, methylergometrine has been reported to contribute to the lowering of milk production and of pituitary prolactin secretion (Peters et al, 1979;Arabin et al, 1986), which may be due to its antiserotoninergic effect (Kato et al, 1974); on the other hand, a controlled study has revealed that methylergometrine had no effecct on lactation and on prolactin (Scapin et al, 1983). Nevertheless, it seems surprising that bromocriptine prevents lactation without producing the typical fall of prolactin to levels within the normal range first described by Besser et al (1972).…”