Diltiazem, nifedipine, nimodipine or verapamil for neuroleptic-induced tardive dyskinesia.
BACKGROUND
Tardive dyskinesia (TD) is a potentially disfiguring movement disorder of the orofacial region often caused by use of neuroleptic drugs. A wide range of strategies have been used to help manage TD and, for those 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.


OBJECTIVE
To determine the clinical efficacy of calcium-channel blockers in people with neuroleptic-induced tardive dyskinesia (TD) and schizophrenia or other chronic mental illnesses.


METHODS
Electronic searches of Biological Abstracts (1982-1995), Cochrane Schizophrenia Group's Register of trials (1995), EMBASE (1980-1995), LILACS (1982-1996), MEDLINE (1966-1995), PsycLIT (1974-1995), and SCISEARCH were undertaken. References of all identified studies were searched for further trial citations. Principal authors of trials were contacted.


METHODS
The inclusion criteria for all relevant randomised studies were that they should focus on people with schizophrenia or other chronic mental illnesses, with neuroleptic-induced TD and compare the use of calcium-channel blockers to placebo or no intervention.


METHODS
No data could be extracted from the two randomised controlled trials that are currently awaiting assessment. The authors have been contacted to provide the relevant information.


RESULTS
No studies met the entry criteria. No data were synthesized.


CONCLUSIONS
Based on currently available information, no confident statement can be made about the effectiveness of calcium-channel blockers for treating people with neuroleptic-induced tardive dyskinesia. Before evaluation of these drugs in larger randomised controlled trials, clinicians should carefully weigh up their possible benefits against their potential adverse effects.
Soares
K V
KV
Dov Hoz Street, 27/16, Kfar Saba, Israel, 44356. ksoares@netvision.net.il
McGrath
J J
JJ
D014150:Antipsychotic Agents / Q000009:adverse effects; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D004110:Diltiazem / Q000627:therapeutic use; D004409:Dyskinesia, Drug-Induced / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D009543:Nifedipine / Q000627:therapeutic use; D009553:Nimodipine / Q000627:therapeutic use; D014700:Verapamil / Q000627:therapeutic use
D014150:Antipsychotic Agents; D002121:Calcium Channel Blockers; D009553:Nimodipine; D014700:Verapamil; D004110:Diltiazem; D009543:Nifedipine