Dopaminergic agonist Ro 8-4650 in Parkinson's disease. I. Patients treated with dopa.

An isoquinoline derivative Ro 8-4650 (rac-4-(3,4-dichlorophenyl)-1,2,3,4-tetrahydro-7-methoxy-2-methylisoquinoline hydrochloride) with dopaminergic properties was studied in a randomized crossover trial. The group studied comprised 37 patients with idiopathic parkinsonism and persistent symptoms, despite levodopa treatment. Median Webster rating before allocation was 11.5. The trial drug did not differ significantly from placebo as regards effect and involuntary movements. It led to more frequent minor side effects.