[Alcohol tolerance in patients with non-insulin-dependent diabetes (type 2) treated orally with drugs--derivatives of sulphonylurea].

The oral ethanol loading test (0.5 g per kg b.m. given as 40% solution) was carried out in 5 groups, each of 10 patients with non-insulin-dependent (type 2) diabetes before and after 10 days of treatment with one of the following sulphonylurea derivatives: tolbutamide 0.5 t.i.d., chlorpropamide 0.5 once daily morning, glibornuride 0.025 t.i.d, glibenclamide 0.005 t.i.d. and glipizide 0.005 t.i.d. The response to alcohol (facial flush, heart rate, blood pressure) were compared, and blood concentration of ethanol, acetaldehyde, pyruvate, lactate, carbonates as well as blood pH, pO2 and pCO2 were determined in fasting state and during 6 hours after alcohol ingestion. In all patients the family history of diabetes and the presence and degree of vascular complications were registered. Evident flushing phenomenon was observed in 6 patients treated with chlorpropamide, in 3 treated with tolbutamide, in 2 treated with glibenclamide, in one receiving glibornuride and in none treated with glipizide. All drugs caused a greater rise of blood ethanol and acetaldehyde levels in relation to the control tests, but the difference reached statistical significance only in the group receiving chlorpropamide. Moreover, patients (pooled) with positive thermographic response had also significantly higher blood levels of ethanol and acetaldehyde during the second test. The ratio of acetaldehyde to ethanol concentration in blood (mumol:mmol) was not significantly changed in any group indicating parallel impairment of both steps of ethanol metabolism. All studied drugs intensified to a similar degree the alcohol-induced hypoglycaemia, but had no significant effect on the decrease of blood pyruvate level neither on the increase of blood lactate level. They didn't change the post-alcohol decrease of blood bicarbonate and pH, and didn't modify the behaviour of partial gas pressure. There was also no difference between pooled groups of patients with positive and negative thermographic reaction with respect to family history of diabetes and frequency and intensity of vascular complications. It is concluded that in patients with non-insulin-dependent (type 2) diabetes the second generation sulphonylurea derivatives are associated with lower risk of alcohol intolerance in case of its incidental ingestion in small amounts. The hypothesis of association of positive thermographic reaction to alcohol during treatment with sulphonylurea derivatives with more frequent occurrence of diabetes in family members and lower tendency to vascular complications was not confirmed.