Methanol and congeners as markers of alcohol use and abuse

Congener analysis and especially methanol contribute to evaluate and differentiate a declared consumption of various alcoholic beverages, e.g. to judge post offence drinking claims. Methanol with serum (or urinary) levels exceeding 10 mg /l cannot be achieved by short time drinking, except with fruit brandy (which can be identified by concomitantly elevated levels of butanol — 2 and MEK (methyl ethyl ketone, as its metabolic product). Numerous results and experiences indicate that methanol, as well as acetone > 7 mg /l and isopropanol > 2 mg /l resp. acetone + isopropanol > 9 mg /l, are markers for recent heavy drinking resp. long periods of alcoholization. At least they indicate alcohol abuse in blood or urine samples taken in alcoholized states or in earlier phases (hours) after drinking. The biological turnover (half time Apr. 2, 4 hours in methanol) has to be considered, which — as generally in marker studies — may affect the outcome of studies with respect to sensitivity. Its main use is more the detection of heavy prolonged drinking as in traffic and social medicine and in intensive care units to recognize possible withdrawals than as a relapse marker. It fits in the time screen of other markers as a short time marker. Methanol metabolism presents interesting aspects in view of the development of addiction and dependency (influence on the C1 metabolism) as well as on hangover and withdrawal.