The contribution of amphetamine metabolites of (-)-deprenyl to its antiparkinsonian properties.

Although (-)-deprenyl is known to be metabolized to methamphetamine and amphetamine, two small-scale double-blind trials indicate that neither metabolite contributes to all therapeutic benefit conferred by this drug in certain patients with Parkinson's disease: the manipulation of urinary pH, which alters the rate of excretion of these metabolites, failed to change the response pattern; substitution of a metabolite mixture for active drug caused a falling off in benefit.