Generic and trade-name antipsychotic drugs: clinical equivalence.

The clinical inequivalence of generic versus trade-name drugs has been reported for nonpsychiatric drugs but rarely for psychotropic drugs. Recent expiration of patents on some psychotropic drugs has made the evaluation of the clinical equivalence of generic versus trade-name drugs a matter of interest from methodological, sociopolitical, and economic aspects. The authors discuss these points, with emphasis on methodology, in their report of a double-blind study of the efficacy of chlorpromazine and Thorazine in the treatment of 54 acute schizophrenic patients. An analysis designed to infer the maximum possible advantage of Thorazine over generic chlorpromazine indicated that differences between the two were clinically insignificant.