Prophylactic antiparkinson drug use: II. Withdrawal after long-term maintenance therapy.

Although the efficacy of long-term neuroleptic treatment of schizophrenic patients is generally accepted, the use of concurrent antiparkinson drugs is less well defined. The value of prolonged antiparkinson drug use in preventing extrapyramidal side effects is controversial. More than 30 studies of antiparkinson drug withdrawal have attempted to answer this question. The authors reviewed all double-blind, placebo-controlled studies, and found most to contain serious methodologic or statistical flaws. There is evidence to support the long-term use of these agents in preventing extrapyramidal side effects. The authors offer an analysis of the benefits and risks that are involved with prophylactic antiparkinson drug use, and conclude that most patients would benefit from maintenance therapy.