Combined antihistamine antagonism of the flushing reaction to alcohol.

The so-called Oriental flushing reaction associated with ingestion of small amounts of alcohol was antagonized by combined antihistamine administration. In stage one of the study, the flushing reaction to low doses of alcohol was produced in Orientals. Most subjects experienced a cutaneous flush, increase in skin temperature, decrease in blood pressure, increase in pulse rate and subjective symptoms such as dizziness, sleepiness, anxiety, headache, generalized weakness and nausea. One half of the group of subjects was then given diphenhydramine, 50 mg (H1 receptor antagonist) and cimetidine, 300 mg (H2 receptor antagonist) and the second half received placebo tablets before the administration of alcohol. The clearest difference between the antihistamine group and placebo group was in the skin flushing reaction. The antihistamine group showed a statistically significant reduction in the skin flush. The antihistamines also neutralized the systolic hypotension induced by the administration of alcohol.