SUPPRESSION OF PROLACTIN SECRETION BY LISURIDE THROUGHOUT THE MENSTRUAL-CYCLE AND IN HYPERPROLACTINEMIC MENSTRUAL DISORDERS

Normally menstruating volunteers as well as patients with hyperprolactinaemic menstrual disorders were treated with lisuride hydrogen maleate (200 μg b.i.d.), an ergoline derivative with dopaminergic properties. Within 3 hr after an oral dose of 200 μg lisuride, PRL levels decreased significantly in all subjects to a plateau which lasted up to 3 hr. Thereafter a gradual increase of serum PRL was noted. In the normally menstruating volunteers lisuride treatment did not result in any significant change of gonadotrophin or of sex steroid secretion, while both basal as well as metoclopramide (MTCL) stimulated PRL release were significantly diminished. The inhibition of PRL secretion in patients with short luteal phases resulted in an increase of luteal progesterone output. In both treated groups ovulation occurred 1 to 5 days earlier in cycles on lisuride than in control cycles. LH-RH/MTCL tests performed in the patient bearing a pituitary prolactinoma before and after lisuride treatment revealed a continuous increase of pituitary LH pools, while PRL secretion decreased under lisuride therapy. Subsequently ovulation and menstruation occurred. The data presented demonstrate that lisuride is a potent inhibitor of PRL secretion and has proven its clinical usefulness for treatment of hyperprolactinaemic menstrual disorders. Application of lisuride resulted in an increase of luteal progesterone secretion in previously demonstrated corpus luteum insufficiency as well as in restoration of normal cyclical feedback mechanisms in tumorous hyperprolactinaemic anovulation. The MTCL-PRL stimulation test is suitable to monitor PRL suppression during lisuride treatment, while LH-RH testing reveals the effectiveness of lisuride by demonstrating an increase of pituitary gonadotrophin pools.