Deprenyl (selegiline) in the treatment of Parkinson's disease.

The effects of deprenyl were investigated in 45 parkinsonian patients suffering from fluctuations in disability under long-term levodopa treatment. During a 1 to 3 month period of treatment, 5-10 mg of deprenyl caused a significant reduction in response fluctuations in 26 out of 45 patients (58%). This improvement was only moderate (58%) or minimal (42%). Of 11 parkinsonian patients taking deprenyl with levodopa and benserazide for up to 4 years, 6 patients (55%) showed moderate and 5 patients (45%) minimal improvement initially. The improvement in response fluctuations was maintained during the follow-up period, although there was a clear decline in the degree of improvement. The addition of deprenyl to levodopa treatment also caused a further improvement in parkinsonian disability, which, however, decreased during the treatment period. Deprenyl appears to be a useful adjuvant to levodopa in patients with daily fluctuations in disability.