The kinetics of methanol elimination in alcoholics and the influence of ethanol.

Methanol concentrations were studied during the end phase of ethanol elimination and for about five hours afterwards in 12 alcoholics admitted with alcohol intoxication for acute care. The rate of ethanol elimination (beta 60) ranged from 0.114 g/kg/h to 0.270 g/kg/h (mean 0.178 +/- 0.045 g/kg/h). The methanol concentration was found to remain almost steady as long as ethanol levels were relatively high, and changed only to an extent that could be explained by the combined opposing influences of methanol excretion and endogenous synthesis. There was no significant relationship between the rate of ethanol elimination and the methanol level. The methanol concentration began to decrease when the ethanol concentration had fallen to under 0.2 g/kg. When the ethanol concentration had fallen to base levels, methanol was eliminated at a rate characterized by an elimination constant (kel) of 0.212-0.481 h-1, and a half life of 1.44-3.27 h. There was a positive correlation between the rate of ethanol elimination and the rate of methanol elimination (r = 0.642; p < 0.05).