The Course of the Blood-Alcohol Curve After Consumption of Large Amounts of Alcohol under Realistic Conditions

Abstract

ABSTRACTThis article presents a review and appreciation of an article by Zink and Reinhardt (Z & R) dealing with the time-course of blood-alcohol curves and pharmacokinetic parameters in healthy men after they drank large amounts of alcohol under controlled real-world conditions. Here we present a reappraisal of this published study to highlight certain aspects of interest for forensic casework, such as when expert testimony is presented on the pharmacokinetics of ethanol. Healthy men, all regular drinkers, consumed large doses of alcohol (3.0–5.7 g/kg body weight) in a social setting for 5 to 10 hours. According to preference, the men drank beer, stomach bitters, or spirits in the company of a girlfriend or spouse. Food was available during the drinking session and the men were allowed to watch video films or play cards. Specimens of venous blood were taken from indwelling catheters every 15 to 30 minutes during and after the end of drinking and the concentrations of ethanol were determined in duplicate by both gas chromatography and enzymatic oxidation. The mean of the four measurements was used to plot concentration-time profiles of alcohol for each subject. The average Cmax was 2.65 g/kg (range 1.92–3.80 g/kg) and tmax occurred at 425 min (range 250–608 min) after the start of drinking. In five of the 14 drinking studies, Cmax occurred before the subjects finished their last drink; mean time to peak after the end of drinking was 2 min (range–56 to 50 min). The rate of alcohol elimination from blood was 0.167 g/kg/h on average (range 0.11 to 0. 26.g/kg/h) and only one subject exceeded 0.20 g/kg/h. The average volume of distribution of alcohol (Widmark's rho factor) was 1.05 (range 0.77–1.32), being considerably higher than expected from knowledge of the water content of the blood and the whole body. The abnormally high rho-factors suggest an appreciable pre-systemic metabolism of alcohol, either in the gut or the liver or both organs, when drinking continues for 5–10 hours. The rate of alcohol elimination from blood was not much different from many bolus dose drinking experiments (mean 0.15 g/kg/h). It seems that continuous heavy drinking for days or weeks is necessary to increase the activity of microsomal enzymes (CYP2E1) and cause a faster elimination rate of alcohol from blood. There were no unexpected irregularities in the concentrations of alcohol between successive blood samples, which does not support the notion of a so-called steepling effect in the post-absorptive state.