Drug Insight: cabergoline and bromocriptine in the treatment of hyperprolactinemia in men and women

Abstract

Prolactinoma is the most frequent pituitary tumor histotype. Men generally have macroadenomas whereas women generally have microadenomas. The major objectives of treating prolactinomas are to suppress excessive hormone secretion and its clinical consequences, to remove the tumor mass while preserving the residual pituitary function, and possibly to prevent disease recurrence or progression. Primary therapy of prolactinomas is based on use of dopamine-receptor agonists. Bromocriptine induces normalization of prolactin levels in 80-90% of patients with microprolactinomas and approximately 70% of those with macroprolactinomas. Tumor-mass shrinkage and improvement of visual-field defects are found in the majority of treated macroprolactinomas, but bromocriptine often causes side effects. Cabergoline is very effective and well tolerated in more than 90% of patients with either microprolactinomas or macroprolactinomas. Cabergoline treatment also induces tumor shrinkage in the majority of patients with macroprolactinomas. Tumor shrinkage is more evident if patients have not previously been treated with other dopamine agonists. Fewer results are available for men than for women, but there is no evidence that men are less responsive to dopamine agonists than are women.

Functioning Pituitary Adenoma

“…If serum prolactin levels are above 200 µg/L, a prolactinoma is almost certainly the underlying cause, but if levels are lower, the differential diagnoses include pregnancy, treatment with drugs (such as neuroleptics) that reduce dopaminergic effects on the pituitary, compression of the pituitary stalk by other pathology, primary hypothyroidism, renal failure, cirrhosis, chest wall lesions, or idiopathic hyperprolactinemia. In the absence of such causes, radiologic imaging of the sella turcica is necessary to establish whether a prolactinoma or other lesions are present (4,6,16).…”

“…The main purpose of treating prolactinomas, both micro-and macroprolactinomas, are to suppress excess hormone secretion and its clinical effects, to remove the tumor mass, and to prevent disease return or progression (16,17). If there is no indication for therapy (such as amenorrhea, infertility or bothersome galactorrhea), microadenomas may be followed conservatively, and regular follow-up with serial prolactin measurements and pituitary imaging should be organized (6,16).…”

“…If there is no indication for therapy (such as amenorrhea, infertility or bothersome galactorrhea), microadenomas may be followed conservatively, and regular follow-up with serial prolactin measurements and pituitary imaging should be organized (6,16). Most prolactinomas can be effectively treated with dopaminergic drugs as primary management.…”

“…Most prolactinomas can be effectively treated with dopaminergic drugs as primary management. For most patients, medical therapy produces normalization of prolactin secretion, gonadal function, and considerable tumor shrinkage in the majority (16). The most commonly used dopamine agonists are bromocriptine, cabergoline (ergot derivatives) as well as quinagolide (a non-ergot derivative) (4,18).…”

“…If patients have not previously been treated with other dopamine agonists, tumor shrinkage is more evident (17). When comparing the plasma half-life, efficacy and tolerability of these drugs, cabergoline seems to have the most favorable profile, followed by quinagolide (16). As a well tolerated and effective therapy and a simple dosing regimen, quinagolide (selective D2 receptor agonist) can also be considered a first-line therapy in the treatment of hyperprolactinaemia (19).…”