Oxypertine in tardive dyskinesia: a long-term controlled study.

A 6-month, double-blind, placebo-controlled study of oxypertine in tardive dyskinesia is described. Results suggest that any beneficial effect noticed initially is not sustained. When this effect is compared with the time course of development of supersensitivity after neuroleptics as reported in the literature, it becomes apparent that the drug, despite its different mechanism of action, behaves like any other conventional neuroleptic. On the basis of the findings, the authors feel that all proposed anti-dyskinetic drugs should be subjected to longer, controlled trials to prove their clinical efficacy.