Noncatecholaminergic treatments of tardive dyskinesia.

We review the results of more than 120 studies of the treatment of tardive dyskinesia with noncatecholaminergic agents. The disorder is thought to arise from dopamine receptor supersensitivity brought on by long term neuroleptic-induced receptor blockade. Ironically, neuroleptics are the most consistently effective treatment of tardive dyskinesia. Nevertheless, it would be desirable to treat it with other compounds. The most intensively studied drugs are the cholinergics, including physostigmine, deanol, choline, and lecithin, but their efficacy has been equivocal. Anticholinergics, opiates, and tryptophan appear to worsen the syndrome or have no effect. Trials of gamma-aminobutyric acid agonists, lithium, and amantadine also produced mixed results. Effectiveness has been claimed for benzodiazepines, estrogens, and pyridoxine,, but the evidence is scant. A small number of preliminary reports on other treatments are also summarized. We discuss briefly the implications of these studies, but methodological problems limit interpretation.