Evaluaton of therapy with cabergoline in men with macroprolactinoa

Abstract

Introduction: Pituitary gland adenomas producing prolactin are one of the commonest hormonally active tumours. Pharmacological treatment using of dopamine receptors agonists is the therapy of choice in a case of prolactinoma. Bromocriptine, which causes numerous side-effects is the most commonly used drug. Recently, good results of therapy have been achieved with cabergoline - a selective dopamine receptor agonist with prolonged time of action. The aim of the study was to evaluate therapy with cabergoline of men with macroprolactinoma based on clinical, hormonal and radiological examinations.

Material and methods: Ten men aged 18-65 (mean 41.9 ?15.01 years) with the presence of a pathological mass in the pituitary gland sized between 16.7 and 40.5 mm (mean 29.8 ± 9.38 mm) and an elevated prolactin (PRL) level of between 37.3 and 4700 ng/mL (mean 1608.2 ±1771.6 ng/mL) were included in the study. The PRL and other trophic hormones levels were evaluated after 1, 3, 6 and 12 months, and tumour size was evaluated by magnetic resonance imaging examination after 12 months of therapy with cabergoline. Results: Therapy with cabergoline led to remission of headaches, visual acuity correction, and a significant improvement in libido and erection in all patients. In 90% of patients, PRL normalisation was achieved, just the initial months of therapy. The mean PRL serum concentrations were before, and after 1, 3, 6 and 12 months of therapy respectively, 1608.2 ± 1771.6 ng/mL and 263.4 ± 223.4, 136.1 ± 244.7,91.31 ± 105.5 and 27.5 ± 57.7 ng/mL. A significant tumour size reduction was observed: from 29.8 ± 9.4 mm to 23.2 ± 9.4 mm, a mean reduction of about 6 mm, or 25.1% (from 4-48.5%). No significant correlation between the mean tumour size and PRL level was observed before or during the treatment. A decreased testosterone level before the therapy was proven, and its gradual increase during the treatment was observed, but after 12 months no normal mean testosterone concentration was achieved.

Conclusions: 1. The administration of cabergoline to patients with macroprolactinoma is effective in reaching PRL level normalisation as well as in tumour size reduction. 2. Therapy with cabergoline significantly decreases the clinical symptoms of hyperprolactinemia and neurological and ophtalmological changes associated with the presence of a pathological lesion in the pituitary gland. 3. Tumour size is not a predictive factor for the effectiveness of therapy with cabergoline.