Therapeutic measures in tardive dyskinesia

Abstract

Studies on the treatments for neuroleptic-induced tardive dyskinesia published in the literature are reviewed. The great number of different treatments and the controversial results of most studies show that there is as yet no specific and safe treatment for tardive dyskinesia. Suggestions for well-designed treatment studies are given: Placebo-controlled double-blind design, larger patient populations, clear diagnostic and standard observing and rating conditions using different assessment methods and videotapes, withdrawal of neuroleptics and antiparkinsonian drugs to discover reversible tardive dyskinesia. If this procedure is not feasible, neuroleptics and other drugs should be maintained at a stable dose level. Longer term studies of some months are necessary to study the prolonged efficacy of different drugs. The effect of dopamine-antagonists such as neuroleptics and of dopamine-depleting agents such as reserpine and oxypertine is of limited duration. Dopamine-agonists such as L-Dopa, bromocriptine and amantadine help only few patients and may even aggravate the symptoms of tardive dyskinesia. In some double-blind studies cholinergic drugs such as lecithin and deanol have improved tardive dyskinesia, but further controlled studies are needed. Anticholinergic drugs such as antiparkinsonian agents should not be prescribed because they may aggravate tardive dyskinesia. Some patients respond to GABA-ergic agents such as baclofen, sodium valproate and the benzodiazepines, but further studies are needed before the value of GABA-ergic agents in the treatment of tardive dyskinesia can be properly assessed. After withdrawal of neuroleptics the average of remission rates within a year is 20%-30%. Elderly patients are more likely to have persistent dyskinesias. A progressive stepwise diminution of the neuroleptic dose and of the antiparkinsonian agents is recommended. When a patient's psychosis is exacerbated after withdrawal of the neuroleptics and tardive dyskinesia is also present, small doses of thioridazine, clozapine or tiapride can be administered. If this practice is not successful cholinergic or GABA-ergic agents may be useful. Because no currently available therapeutic agents satisfies the criteria of safety, marked effectiveness and prolonged efficacy in the treatment of tardive dyskinesia, prevention becomes more important. Prolonged use of a neuroleptic medication requires careful evaluation of indications and risks. The doses of neuroleptic drugs during the maintenance treatment of schizophrenia should be as small as possible.