Suppression of acetaldehyde accumulation by 4-methylpyrazole in alcohol-hypersensitive Japanese

Alcohol-sensitive Japanese subjects with facial flushing and an increase in heart rate during ethanol intoxication exhibited marked individual variation in accumulation of acetaldehyde. This variation correlated well with the intensity of the above mentioned physiological responses. Oral pretreatment with 10 mg/kg 4-methylpyrazole, which inhibited the ethanol elimination rate by 15-25%, strongly suppressed both acetaldehyde accumulation and the associated responses. Under this condition, the sensitivity to acetaldehyde appeared to be reduced, and the correlation between the acetaldehyde level and the physiological responses disappeared. The effectiveness of even a low dose of 4-methylpyrazole suggests its clinical usefulness for alleviation of acute acetaldehyde toxicity in alcohol-hypersensitive Japanese individuals as well as in disulfiram-treated alcoholics.