Parkinson's disease: long-term results of levodopa therapy.

The long-term results of levodopa therapy in Parkinsonian patients is described. Between January 1969 and December 1972, dopaminergic therapy was started in 186 patients with Parkinson's disease. Their progress after six months, five years and in the autumn of 1980, was assessed. The initial benefit in the majority of patients was followed by a gradual loss of efficacy in most patients with increasing side effects of central-mediated type. We suggest that it may be wise to delay the onset of levodopa therapy until progress of the disease makes treatment imperative.