Toxicity of ethanol-barbiturate mixtures

Abstract

The simultaneous administration of ethanol at doses of either 2, 3, or 4 g/kg intraperitoneally produced a dose-related decrease in the intraperitoneal LD50 for thiopentone, pentobarbitone, amylobarbitone, phenobarbitone and barbitone in rats. The most marked ethanol-barbiturate interaction was with the long-acting, poorly metabolized, less potent barbiturates phenobarbitone and barbitone. Similarly, a non-hypnotic dose of ethanol (3 g/kg, i.p.) produced a much greater prolongation of the sleeping time with non-hypnotic doses of phenobarbitone and barbitone, than with threshold doses of the shorter acting barbiturates. Various postulates are advanced to explain the underlying mechanism of the barbiturate-ethanol interaction.