Chloral hydrate enhances ethanol-induced inhibition of methanol oxidation in mice

Several studies indicated that chloral hydrate can prolong the disappearance time of ethanol from blood in mice. This seems to result from inhibition of the enzyme alcohol dehydrogenase by chloral hydrate and trichloroethanol, its main metabolite. We examined the effect of both these compounds on the disappearance time of methanol in mice. Also the effect of a combination of ethanol and chloral hydrate on the disappearance time of methanol was examined. Several groups of six mice each received methanol (1 g/kg i.p.) followed immediately by one of the following treatments: saline (10 ml/kg); chloral hydrate (0.4 g/kg); trichloroethanol (0.36 g/kg); ethanol (4 g/kg); or a combination of chloral hydrate (0.2 g/kg) and ethanol (4 g/kg). The concentrations of methanol in blood were measured at 1, 2, 4, and 8 h after its administration and were used to calculate some approximate indicators of methanol elimination in each group. The results show that all the above treatments do prolong the disappearance time of methanol in the blood of mice to varying extents. The ethanol-chloral hydrate combination produced the most pronounced effect.