Alcohol levels are increased in social drinkers receiving ranitidine

OBJECTIVE: Ranitidine increases blood alcohol concentrations by decreasing the first pass metabolism of ethanol. The effect of ranitidine on alcohol l evels has been found to be variable when using large doses of alcohol or co nditions in which its first pass metabolism is known to be minimal. Despite a consensus that the drug increases alcohol levels after small doses of et hanol, this effect has been considered inconsequential, because of the low alcohol levels. However, social drinking comprises repetitive consumption o f small doses of alcohol and the ranitidine effect could thereby be potenti ated. METHODS: To study this factor, alcohol levels were determined by breath ana lysis in nine men (social drinkers), after four drinks of 0.15 g/kg ethanol given postprandially every 45 min, before and after ranitidine (150 mg b.i .d. for 7 days). RESULTS: Their blood alcohol increased with repeated doses, reaching peak v alues of 24 +/- 3 mg/dl before ranitidine and 33 +/- 2 after ranitidine (p = 0.04). In seven of the nine subjects blood alcohol exceeded 25 mg/dl, a l evel at which impairment of judgment and of finely tuned skills occurs and which exceeds legal limits of driving in some European countries. Moreover, the high levels persisted for a longer time with than without the drug. Th ese effects were associated with a 62% decrease in first pass metabolism. CONCLUSION: Under conditions mimicking social drinking, ranitidine increase s blood alcohol to levels known to impair psychomotor skills needed for dri ving. (Am J Gastroenterol 2000;95:208-213. (C) 2000 by Am. Cell. of Gastroe nterology)