Treatment of prolactinomas

The objectives of the treatment of hyperprolactinaemia are to suppress excessive hormone secretion and its clinical consequences, to remove tumour mass, to preserve the residual pituitary function and to prevent disease recurrence or progression. Prior to the advent of pharmacotherapy, therapy usually consisted of surgical resection and/or pituitary irradiation. In microprolactinomas, trans-sphenoidal surgical resection normalizes prolactin (PRL) levels, restores normal menses and produces the disappearance of galactorrhoea in a great majority of patients, but normalization of serum PRL levels varies from 35-70%. In macroprolactinomas, trans-sphenoidal surgery is less successful with only 32% of patients appearing to be cured initially. However, the recurrence rate is 19%, and the long-term cure rate is only 26%. In more than 80% of the patients with microprolactinoma, suppression of PRL levels and tumour shrinkage can be achieved with bromocriptine therapy given at doses of 2.5-5 mg per day. In 5-10% of the patients, the appearance of side-effects (nausea, dizziness and postural hypotension) is a limiting factor in continuing the treatment. Dopaminergic compounds cause notable tumour shrinkage in most macroprolactinomas. Treatment with cabergoline, a selective and long-lasting dopamine 2-receptor agonist at weekly doses of 0.5-2 mg has been shown to be effective both in normalizing PRL levels and in inducing tumour shrinkage. Pharmacotherapy with dopamine (DA) agonists is an appropriate first-line treatment for both micro- and macroprolactinomas. Surgery should be recommended for those patients who are severely intolerant of or resistant to DA agonists.