Selective D-1 dopamine receptor agonist treatment of Parkinson's disease.

Preclinical evidence suggests that the D-1 dopamine receptor contributes to the generation of behaviors used as models for human extrapyramidal disorders. To evaluate the potential of D-1 receptor stimulation in neurologic disease, SKF 38393, a selective D-1 dopamine receptor agonist, was administered to seven patients with idiopathic Parkinson's disease in a double-blind, placebo controlled study. SKF 38393 was found to be rapidly absorbed when administered orally, and to occur in micromolar concentrations in spinal fluid. No change in scores of parkinsonian severity were noted when SKF 38393 was administered alone, or when the drug was combined with intravenous levodopa. The results support the view that the pathophysiology of Parkinson's disease may relate exclusively to the D-2 subclass of dopamine receptors.