CABERGOLINE TREATMENT RAPIDLY IMPROVES GONADAL-FUNCTION IN HYPERPROLACTINEMIC MALES - A COMPARISON WITH BROMOCRIPTINE

This study evaluated the effects of chronic treatment with cabergoline (CAB), a new, potent and long-lasting ergoline-derived dopamine agoni st, on seminal fluid parameters and sexual and gonadal function in hyp erprolactinemic males in comparison with the effect of bromocriptine ( BRC) treatment. Seventeen males with macroprolactinoma were treated wi th CAB at a dose of 0.5-1.5 mg/week (n = 7), or BRC at a dose of 5-15 mg/day (n = 10) for 6 months. Baseline prolactin (PRL) was 925.7 +/- 5 22.6 mu g/l in the CAB-treated group and 1059.4 +/- 297.6 mu g/l in th e BRC-treated group. All the patients suffered from libido impairment, ten from reduced sexual potency, and six had infertility. In five pat ients provocative bilateral galactorrhea was found. Seminal fluid anal ysis, functional seminal tests and penis rigidity and tumescence, meas ured by nocturnal penile tumescence (NPT) using Rigiscan equipment, we re assessed before and after 1, 3 and 6 months of CAB or BRC treatment . Hormone profiles were assessed before and af ter 15, 30, 60, 90 and 180 days of both treatments. Before treatment, all patients had a low sperm count with oligoasthenospermia, reduced motility and rapid progr ession with abnormal morphology and decreased viability, and a low num ber of erections. After 1 month, serum PRL levels were significantly r educed in both groups of patients (20.6 +/- 6.6 mu g/l during CAB and 256.3 +/- 115.1 mu g/l during BRC treatment) and were normalized after 6 months in all patients (CAB: 7.9 +/- 2.2 mu g/l; BRC: 16.7 +/- 1.8 mu g/l). After 6 months, a significant increase of number, total motil ity, rapid progression and normal morphology was recorded in patients treatment with both CAB and BRC. An increase in the number of erection s during the first 3 months of both treatments was noted by NPT. Howev er, the improvements in seminal fluid parameters and sexual function w ere more evident and rapid in patients treated with CAB. The number of erections was normalized after 6 months of treatment in all patients submitted to CAB treatment, and in all patients but one treated by BRC . In addition, a significant increase of serum testosterone (from 3.7 +/- 0.3 to 5.3 +/- 0.2 mu g/l) and dihydrotestosterone (from 0.4 +/- 0 .1 to 1.1 +/- 0.1 nmol/l) was recorded. At the beginning of treatment, mild side-effects were recorded in two patients after CAB and mild-to -moderate side-effects in five patients after BRC administration. The treatment with CAB normalized PRL levels, improving gonadal and sexual function and fertility in males with prolactinoma, earlier than did B RC treatment, providing a good tolerability and excellent patient comp liance to medical treatment.