The oral ethanol loading test (0.5 g/kg body mass) was carried out in 3 groups with 10 healthy male volunteers each before and after 7 days of administration of either cimetidine (CAS 51481-61-9), ranitidine (CAS 66357-59-3), or famotidine (CAS 76824-35-6). The parameters determined during 6 h comprised the blood levels of ethanol, acetaldehyde, glucose, lactate, pyruvate and bicarbonates, as well as blood pH, PCO2 and PO2. Only ranitidine significantly increased the mean blood ethanol concentration and none of the drugs modified the blood acetaldehyde concentration. Hypoglycaemia following alcohol ingestion was significantly enhanced by all H2-receptor antagonists, but was most pronounced after famotidine. The alcohol-induced rise in blood pyruvate and lactate rather had a tendency to decrease during the second test. The presented results suggest that the evident enhancement of alcohol-induced hypoglycaemia by H2-receptor antagonists is not dependent on the increase of ethanol absorption from the gastrointestinal tract, but represents rather a specific effect of these drugs on glucose metabolism.