Recent advances in the clinical pharmacology of Parkinson's disease.

The introduction of levodopa in the treatment of Parkinson's disease had modified both the prognosis and the current concepts of the disease, Although levodopa remains the most potent drug for the treatment of Parkinson's disease, its long-term use is associated with fluctuations in motor performance, abnormal movements and psychotic hallucinations. These late side-effects remain difficult to treat and thus raise questions as to the benefits and risks of first-time treatment with levodopa. Levodopa mainly alleviates akinesia and rigidity and to a lesser extent, tremor. Levodopa increases life expectancy. This paper reviews some recent developments in the pharmacology of Parkinson's disease. Recent findings indicate that not only central dopamine but also several other central neurotransmitter and receptor changes are involved in the pathophysiology of Parkinson's disease. New data on autonomic dysfunction in Parkinson's disease are presented. New methods of investigation (clinical rating scales, pharmacological tests, imaging techniques, etc.) are reviewed. Finally, future strategies, e.g. the development of potent new symptomatic drugs (selective D2 and D1 agonists, new formulations of apomorphine, COMT inhibitors, new routes of administration, etc.) and etiopathogenic agents (antioxidative and anti-free radical drugs, etc.) are discussed.