Vitamin E in the treatment of tardive dyskinesia

OBJECTIVE: TO review the efficacy of vitamin E in the treatment of tardive dyskinesia (TD), DATA SOURCES: Published articles and abstracts in English were identified from January 1986 to March 1999 by MEDLINE and International Pharmaceutical Abstracts searches using the terms vitamin E, alpha-tocopherol, and tardive dyskinesia. Additional articles were identified from the references of the retrieved articles and cross-referencing selected articles. DATA EXTRACTION: All clinical trials evaluating the use of vitamin E in human subjects with TD were reviewed. Selected articles also included those considered to be helpful in providing a basic introduction to TD pathophysiology and management. DATA SYNTHESIS: TD occurs in approximately 20% of patients treated with neuroleptics. The resulting dyskinesias can be irreversible and are often psychologically and physically debilitating. Recent research suggests that TD may be a result of neuronal damage inflicted by free radicals generated from increased neurotransmitter turnover and metabolism. Vitamin E as a naturally occurring free radical scavenger has been evaluated in the treatment of TD. Eighteen completed trials are available either in completed or abstract form. Twelve of these trials have produced positive results with vitamin E in the treatment of TD, Patients who have had TD for less than five years appear to respond better than patients with long-standing TD. CONCLUSIONS: Research suggests that vitamin E offers benefit in the management of a subgroup of patients with TD. Further investigation is needed to ascertain continued efficacy with longterm use as well as the role of vitamin E in TD prophylaxis.