Is ethanol metabolism affected by oral administration of cimetidine and ranitidine at therapeutic doses?

The aim of this study was to compare the ethanol serum concentration curve, the area under the curve and subjective response after acute ingestion of ethanol (red wine, 13 degrees proof, at a dose of 0.8 g/kg of ideal weight in 6 healthy volunteers with a mean habitual alcohol intake of 20 g/day. All the subjects underwent the test a total of three times, after pre-treatment with cimetidine (400 mg X 2/day/7 days) and ranitidine (150 mg X 2/day/7 days), respectively, and after receiving no pre-treatment. The wine was taken orally within the space of 15 min, four hours after taking a standard-weight ham sandwich. Blood samples were drawn at the following times: 0, 30, 60, 90, 120, 180, 240 and 360 minutes. The plasma ethanol curve of the subjects pre-treated with cimetidine lies above that of the subjects pre-treated with ranitidine, and largely coincides with the curve obtained in those who received no pre-treatment, with the exception of the initial hour-and-a-half, when the later show a slightly higher mean plasma concentration. The differences between the three treatment groups are merely arithmetical, but not statistical, with respect to peak plasma ethanol concentrations, time elapsing before peaking, and areas under the curves. These results are at variance with some published data suggesting a significant interaction of cimetidine with the metabolism of alcohol by way of interference either with the hepatic oxidative metabolizing enzymes, or with the activity of alcohol dehydrogenase.