[Treatment of Parkinson's disease with multiple drugs]

All major symptoms of Parkinson's disease, i.e., rigidity, tremor, hypokinesia and postural instability are induced by an impaired dopaminergic neurotransmission in the nigro-striatal pathway. Levodopa pioneered the symptomatic therapy of Parkinson's disease. While it is effective on the motor symptoms, long-term levodopa therapy often results in dyskinesia, motor fluctuations and psychosis. Coadministration of levodopa and dopamine agonists, bromocriptine and pergolide, decreases these adverse side effects. Anticholinergics and amantadine are often effective as adjuvant drugs for the early stage of patients with Parkinson's disease. Furthermore, L-threo-DOPS, nor-adrenergic precursor drug, is sometimes effective for the advanced stage of Parkinson's disease. Thus coadministration of multiple antiparkinsonian drugs, rather than single therapy of levodopa, is useful for the long-term treatment of Parkinson's disease.