Long-term efficacy of pergolide in patients with Parkinson's disease.

We report the clinical course of 35 patients with Parkinson's disease who experienced an initially favorable response to pergolide and who were taking the drug for at least 6 months. The duration of pergolide treatment was 6-50 (25 +/- 16 SD) months. Of the 14 patients who remained on pergolide for over 2 years, 12 remained less disabled for 26 +/- 17 SD months, seven enjoyed increased "on" time for 39 +/- 8 SD months, and nine had a lower Hoehn-Yahr stage for 25 +/- 17 SD months. Pergolide was discontinued after 5-39 months in eight patients; six patients then deteriorated. Pergolide can remain efficacious in the treatment of Parkinson's disease for up to 50 months.