Dopamine receptor agonists for treating prolactinomas

Abstract

Prolactinomas are the most common hormone-secreting pituitary tumours and cause infertility and gonadal and sexual dysfunction in both sexes. The approach to prolactinomas has changed in the last 25 years thanks to the availability of dopaminergic drugs characterised by a potent prolactin-inhibitory effect, a tumour shrinking effect associated with a satisfactory tolerability. In more recent years, cabergoline (1-[(6-allelylergolin-8β-yl)carbonyl]-1-[3-(dimethylamino) propyl]-3-ethyl-urea), an ergoline derivative with potent, selective and long-lasting inhibitory activity on prolactin release, has been used to suppress prolactin secretion in women with hyperprolactinaemia. Cabergoline was shown to be significantly more effective than bromocriptine in inducing a complete biochemical response and clinical efficacy and was better tolerated than bromocriptine in the majority of patients. Notable tumour shrinkage until tumour disappearance was observed during cabergoline treatment in most patients with macroprolactinoma and it was also proven effective in patients resistant to or with a poor response to bromocriptine. In view of the limited data on cabergoline-associated pregnancies and the long half-life of the drug, it is currently recommended that women hoping to become pregnant, once ovulatory cycles have been established, should discontinue cabergoline therapy 1 month before they intend to conceive. However, no data concerning negative effects on pregnancy or offspring have been reported. The great efficacy of this compound together with its excellent tolerability makes this drug the current treatment of choice for the majority of patients with hyperprolactinaemic disorders.