Disease Information for Bromocriptine (Parlodel) Administration/Toxicity

Anti-parkinsonism drug; CNS Dopamine agonist drug ergot derivative; used in prolactinemia and acromegaly and as anti-parkinsonism drug; oral preparation---------------------------

Dopamine agonists

Dopamine agonists act directly on dopamine receptors, and their use in parkinsonism is associated with a lower incidence of the response fluctuations and dyskinesias that occur with long-term levodopa therapy. They were previously reserved for patients who had either become refractory to levodopa or developed the "on-off phenomenon." However, they are now best given either before the introduction of levodopa or with a low dose of Sinemet 25/100 (carbidopa 25 mg and levodopa 100 mg), one tablet three times daily when dopaminergic therapy is first introduced; the dose of Sinemet is kept constant, while the dose of the agonist is gradually increased. Two agonists, are bromocriptine and pergolide, are ergot derivatives. The initial dosage of bromocriptine is 1.25 mg twice daily; this is increased by 2.5 mg at 2-week intervals until benefit occurs or side effects limit further increments. The usual daily maintenance dose in patients with parkinsonism is between 10 and 30 mg. Pergolide is similarly started in a low dose (eg, 0.05 mg daily) and built up gradually depending on the response and tolerance.------------------------------------------------------

Side effects include anorexia, nausea, vomiting, constipation, postural hypotension, digital vasospasm, cardiac arrhythmias, various dyskinesias and mental disturbances, headache, nasal congestion, erythromelalgia, and pulmonary infiltrates. There are rare reports of pericardial, pleural, or pulmonary fibrosis; pergolide has also been associated with cardiac valvopathy. Bromocriptine and pergolide have largely been replaced with other agents because of these side effects.

[current dxrx 2005 accessmedicine.com]

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