Medical therapy of prolactinomas

Abstract

Bromocriptine therapy normalizes prolactin levels and restores fertility in 82 to 90% of patients with prolactinoma. Tumour diameter is reduced (> 25%) in 60 to 79% of patients within 3 to 12 months. Symptoms return in the majority of cases, even after 1.5 to 10 years of treatment, if the drug is withdrawn; thus, in macroprolactinoma, life-long dopamine agonist treatment is indicated. A depot formulation of bromocriptine has been introduced which allows 50 to 100 mg of bromocriptine to be administered at monthly intervals. Treatment resulted in normalization of prolactin levels in 72% of cases and a tumour shrinkage (> 25%) was noted in 54%. This preparation is well tolerated, apart from initial injection. CV 205-502 is a non-ergot long-acting dopamine agonist. A daily dose of 75 to 400 micrograms reduced hyperprolactinaemia in 58 to 91% of patients and induced tumour shrinkage in 52%. CV 205-502 achieved normal prolactin levels in 50% of patients previously diagnosed as bromocriptine-resistant. Cabergoline is an ergot derivative. A twice weekly dose of 0.2 to 3.5 mg induced tumour shrinkage in 96% of patients treated. Pergolide is another potent dopamine agonist and is expected to give similar results to cabergoline and CV 205-502.