Bromocriptine in obstetrics and gynaecology.

Bromocriptine, the active ingredient of Parlodel is a specific dopamine receptor agonist available for use in clinical practice. It has been successfully used in the treatment of hyperprolactinemia with associated amenorrhea, galactorrhea and infertility; in the inhibition of postpartum lactation; acromegaly and in Parkinson's disease. Its role in obstetrics and gynaecology is strategic since it restores gonadal function and fertility. It decreases the size of prolactin secreting pituitary tumors, and has been used with varying degrees of success in the treatment of menstrual disorders, premenstrual syndrome and polycystic ovarian disease. Its role in the treatment of carcinoma cervix is beneficial, but not proven. Withdrawal of bromocriptine therapy however is associated with reversal of its beneficial effects and return of hyperprolactinemia. In this article the current knowledge about the pharmacologic effects and individual clinical applications oLbromocriptine pertaining to obstetrics and gynaecology have been reviewed. Pharmacology 2 Br-alpha-ergokryptine mesylate (Bromocriptine) is a semisynthetic ergot alkaloid, that was specifically developed in 1967, as an inhibitor of prolactin secretion. It was introduced into clinical research in 1969 and was shown to directly stimulate neuronal dopamine receptors 1-3. Since prolactin is undertonic inhibition of dopamine 4,5 bromocriptine acting as a receptor agonist markedly inhibits its secretion 6. After oral administration, 28% is absorbed from gastrointestinal tract, and peak plasma concentration. is achieved 1 to 3 hours after ingestion 2,3. First pass metabolism of the absorbed dose is extensive (94%) and only 6% reaches the systemic circulation unchanged. Excretion occurs exclusively in faeces (98%) and only 2% of the dose appears in urine 1-3. Serum prolactin levels remain suppressed for about 14 hours after a single dose and after that no bromocriptine is detectable in circulation 2. Side effects can be separated into two major groups, those noticed with initiation of therapy and those associated with long term treatment. Initial effects include nausea, vomiting and orthostatic hypotension, that can be minimized by starting therapy with alow dose given at bed time with food, and gradually increasing it until a therapeutic response is achieved ,3 With long term treatment headache, fatigue, abdominal cramps, constipation, nasal congestion and digital vasospasm may be noted. Intense visual hallucinations, erythromelalgia, reversible, pleuropulmonary changes including pleural thickening and effusion and even urinary incontinence have been described 2,3,7. The therapeutic role of bromocriptine in different disorders is discussed below. Hyperprolactinemia Hyperprolactinemia is an increasingly recognized cause of amenorrhea, galactorrhea and infertility in females …