Biphasic effects of alcohol drinking on methamphetamine metabolism in man.

In methamphetamine (MAP) addicts, long-term ethanol ingestion 3-4 times per week induced an increased rate of p-hydroxylation of MAP and amphetamine (AMP). Simultaneous ingestion of ethanol and MAP inhibited both p-hydroxylation of MAP and AMP and N-demethylation of MAP in inebriated addicts. The p-hydroxylation of MAP and AMP was also significantly inhibited in daily drinkers despite the almost total absence of urinary ethanol. This suggests that the intensity of MAP-induced behavioral and psychological effects in MAP addicts may, in part, depend upon their drinking habits.