Fenfluramine hydrochloride treatment of parkinsonism.

The oral administration of fenfluramine hydrochloride, which acts centrally to augment serotonin-mediated synaptic function, did not alter extrapyramidal signs in either untreated or levodopa-treated parkinsolian patients. These results support the contention that biochemical indices of serotonergic dysfunction in Parkinson disease do not reflect a critical role for serotonin-containing neural systems in the pathophysiology of parkinsonism and that serotonin-active drugs afford no significant therapeutic benefit to patients with this disorder.