CV 205-502: safety, tolerance to, and efficacy of increasing doses in patients with Parkinson's disease in a double-blind, placebo crossover study.

CV 205-502 (CV) is a long-acting dopamine agonist with potent D2 and weak D1 activity, which has not as yet been tested in patients with Parkinson's disease. We performed a dosage ranging and placebo crossover study in six patients to evaluate the efficacy and tolerance of CV when used as an adjunct to Sinemet in patients with Parkinson's disease. All patients had striking improvement. This effect was lost with placebo substitution and regained with reintroduction of CV. Benefits were sustained throughout the 6 month study. Single daily dosing could sustain the response in all but one patient. Adverse effects were mild and transient and resolved with dosage manipulation or a divided dosage regimen. CV is a promising drug for use in Parkinson's disease and further studies are indicated to test its long-term safety and efficacy.