Effect of chlorpromazine on blood level of alcohol in rabbits

¹ Department of Pharmacology, University of California School of Medicine; and The Langley Porter Neuropsychiatric Institute, California Department of Mental Hygiene, San Francisco, California

It was previously observed in man that chlorpromazine elevated the blood alcohol level above that expected after a standard dose of ethanol. The present study shows a similar elevation of blood alcohol in rabbits; furthermore, this elevation occurs whether the ethanol is given orally or intravenously. The magnitude of the elevation is less with intravenously administered alcohol. Since an increased absorption rate might explain this difference in magnitude, a detailed analysis of factors influencing absorption was done. Since chlorpromazine inhibits the sympathetic nervous system centrally and the parasympathetic peripherally, other autonomic blocking agents were studied for their effects on the blood alcohol level: reserpine was used for central sympathetic inhibition, atropine for peripheral parasympathetic inhibition, and hexamethonium for dual inhibition. Since none of these agents affected the blood alcohol level, nor did chlorpromazine elevate the blood level of other substances absorbed in a manner similar to ethanol, it was concluded that no part of the effect was due to an increase in absorption but that the effect probably was due entirely to an inhibition of metabolism.