Are calcium-channel blockers effective in the treatment of tardive dyskinesia?

OBJECTIVE: To review the data describing the use of calcium-channel blockers in the treatment of tardive dyskinesia (TD). DATA SOURCES: A MEDLINE search of the English-language literature and a bibliographic review of pertinent articles examining the use of calcium-channel blockers in the treatment of TD were performed. Medical Subject Headings (MESH) terms used were calcium-channel blockers, tardive dyskinesia, nifedipine, verapamil, and diltiazem. STUDY SELECTION AND DATA EXTRACTION: Relevant case reports, open trials, and controlled studies reporting on the efficacy of calcium-channel blockers for treating TD are reviewed. Appropriate conclusions are drawn from the data and guidelines are suggested for the practitioner. DATA SYNTHESIS: Studies addressing the efficacy of calcium-channel blockers in the palliative treatment of TD have yielded mixed results. Positive findings have been reported for nifedipine, verapamil, and diltiazem; nifedipine may be the most efficacious treatment and diltiazem the least. It appears that patients with TD who can tolerate higher doses of calcium-channel blockers may respond more favorably to treatment. Patient characteristics that may help determine a better response to treatment with calcium-channel blockers include advanced age and more-severe TD. CONCLUSIONS: To determine the efficacy of calcium-channel blockers in the treatment of TD, additional data are needed from double-blind, placebo-controlled studies with larger sample sizes and longer durations of treatment. Until these data are available, calcium-channel blockers should be considered potentially useful therapy for the heretofore unresponsive TD.