CABERGOLINE - A REVIEW OF ITS PHARMACOLOGICAL PROPERTIES AND THERAPEUTIC POTENTIAL IN THE TREATMENT OF HYPERPROLACTINEMIA AND INHIBITION OFLACTATION

Cabergoline is a synthetic ergoline which shows high specificity and a ffinity for the dopamine D-2 receptor. It is a potent and very long-ac ting inhibitor of prolactin secretion. Prolactin-lowering effects occu r rapidly and after a single dose, were evident at the end of follow u p (21 days) in puerperal women, and rip to 14 days in patients with hy perprolactinaemia. In the only comparative study to date, cabergoline 0.5 to 1.0mg twice weekly was more effective than bromocriptine 2.5 to 5.0mg twice daily in the treatment of hyperprolactinaemic amenorrhoea , restoring ovulatory cycles in 72% of women and normalising plasma pr olactin levels in 83%, compared with 52 and 58%, respectively for brom ocriptine. In the prevention of puerperal lactation, a single dose of cabergoline 1.0mg was as effective as bromocriptine 2.5mg twice daily for 14 days. A significantly low er incidence of rebound lactation in the third postpartum week was seen with cabergoline. Unpublished data suggest cabergoline 0.25mg twice daily for 2 daps is effective in supp ressing established puerperal lactation in about 85% of women. Nausea, vomiting, headache and dizziness are characteristic adverse events of the dopaminergic ergot derivatives. Cabergoline appears to be better tolerated than bromocriptine in both patients with hyperprolactinaemia and postpartum women. Most patients intolerant of other ergot derivat ives can tolerate cabergoline. Bromocriptine rise in the puerperium ha s been associated with an increased risk of serious thromboembolic eve nts. However there are no such reports with cabergoline and whether th ese events will become associated with other dopaminergic agents is un known. The teratogenic potential of cabergoline has not been extensive ly investigated in humans. Ten congenital abnormalities have been repo rted in 199 cabergoline-associated pregnancies. Although there is no p attern to these abnormalities, the limited experience with cabergoline in pregnancy means the drug cannot be considered as a first-line ther apy for the treatment of infertility associated with hyperprolactinaem ia. At this stage of its development, cabergoline will prove useful in patients with hyperprolactinaemia who have failed treatment with, or are intolerant of other dopamine agonists such as bromocriptine. If dr ug treatment is required for the prevention or suppression of puerpera l lactation, cabergoline offers significant advantages over bromocript ine and should become the drug treatment of first choice for this indi cation.