Treatment of tardive dyskinesia: use of dopamine-depleting agents.

Four different clinical syndromes encompassing the TD spectrum are described: (a) classical TD, which is choreatic in speed of movement and stereotypic in pattern; (b) tardive akathisia; (c) withdrawal emergent syndrome, which presents as true chorea; and (d) tardive dystonia, which presents with dystonic movements and postures. All are made worse or are unmasked by withdrawal of the antipsychotic drugs, and all tend to be reduced in severity by increasing the dosage of the antipsychotic drugs (dopamine-receptor blockers) or utilizing presynaptically acting dopamine-depleting drugs. Treatment depends on discontinuing the causative agent, i.e., the antipsychotic drugs. The withdrawal emergent syndrome is self-limiting. Classical TD and tardive akathisia are persistent. The dopamine-depleting agents can be utilized if the symptoms are severe. Reserpine alone or with AMT is effective in most cases. Tetrabenazine can be substituted for reserpine. With time, the disorder can eventually disappear in many patients as long as the antipsychotic drugs have been eliminated. Carbidopa/levodopa (Sinemet) can be added to counteract parkinsonian symptoms that occur as an adverse effect of these medications. The addition of Sinemet may be useful in hastening a remission of TD. Tardive dystonia is less successfully treated. Some patients will respond to the approach used to treat classical TD, others may respond to anticholinergic agents, and some remain resistant to these methods. They may require reinstitution of the antipsychotic drugs.