Calcium channel blockers for neuroleptic-induced tardive dyskinesia.

Abstract

Tardive dyskinesia is a disfiguring movement disorder of the orofacial region often caused by antipsychotic drugs. A wide range of strategies has been used to help manage tardive dyskinesia and, for people who are unable to have their antipsychotic medication stopped or substantially changed, the calcium-channel blocking group of drugs (diltiazem, nifedipine, nimodipine, verapamil) has been suggested as a useful adjunctive treatment. To determine the effects of calcium-channel blocker drugs (diltiazem, nifedipine, nimodipine, verapamil) for treatment of neuroleptic-induced tardive dyskinesia in people with schizophrenia, schizoaffective disorder or other chronic mental illnesses. We updated previous searches of the Cochrane Schizophrenia Group Register (1982-2000), Cochrane Library (Issue 4, 2000), Cochrane Schizophrenia Group's register of trials (November 2000), EMBASE (1980-2000), LILACS (1982-2000), MEDLINE (1966-2000), PsycLIT (1974-2000), and SCISEARCH by searching the Cochrane Schizophrenia Group Register (September 2003). We searched references of all identified studies for further trial citations and contacted authors of trials. Randomised clinical trials comparing calcium-channel blockers to placebo or no intervention for people with both tardive dyskinesia and schizophrenia or serious mental illness. Data were to have been independently extracted and analysed on an intention-to-treat basis. The relative risk (RR) and 95% confidence intervals (CI) of homogeneous dichotomous data were to have been calculated using a random effects model, and, where possible, the number needed to treat calculated. Weighted mean differences (WMD) were to have been calculated for continuous data. No trials were included. We excluded fourteen studies; eight were not randomised, one did not use calcium channel blockers and five small, randomised, studies reported no usable data. The effects of calcium-channel blockers for antipsychotic induced tardive dyskinesia are unknown. Their use is experimental and should only be given in the context of well designed randomised studies.