Adverse effects in the treatment of Parkinson's disease.

Side effects to antiparkinsonian drugs constitute an important component of the daily management of patients with Parkinson's disease. Treatment with levodopa frequently leads to motor fluctuations and dyskinesias. Hallucinosis, nausea and vomiting, drowsiness, orthostatic hypotension and peripheral edema can be managed by dose reduction, medication substitution and specific counteractive measures. Anticholinergics frequently cause cognitive or autonomic symptoms while ergot-derived dopamine agonists carry unique, albeit rare, risks of fibrotic, vasoconstrictive and dermatological side effects. Current areas of controversy include: dopamine agonist-induced sleep attacks, increased mortality with the combination of selegiline and levodopa and the association of levodopa with melanoma.