Clonazepam treatment of tardive dyskinesia: a practical GABAmimetic strategy.

Because of the efficacy of specific gamma-aminobutyric acid (GABA) agonists in tardive dyskinesia, the authors tested the benzodiazepine clonazepam in a 12-week, double-blind, placebo-controlled, randomized crossover trial in 19 chronically ill patients with tardive dyskinesia who were being treated with neuroleptics. They found a 35% decrease in dyskinesia ratings with clonazepam treatment. The six patients with predominantly dystonic symptoms showed greater benefit than the 13 patients with predominantly choreoathetoid dyskinesias. Tolerance developed to the antidyskinetic effect of clonazepam in the five patients whose long-term use of the drug was followed, but a 2-week clonazepam-free period recaptured its antidyskinetic effect.