Pharmacokinetics of Phosphatidylethanol 16:0/20:4 in Human Blood After Alcohol Intake.

Background: The purpose of this study was to characterize the pharmacokinetics of the phosphatidylethanol (PEth) 16:0/20:4 homolog in uncoagulated human blood samples taken from 18 participants in a clinical laboratory setting after consumption of 2 standard doses of ethanol (EtOH). Methods: Male and female participants received either 0.4 or 0.8 g/kg oral doses of EtOH during a 15‐minute period. Blood samples were collected before and throughout 6 hours immediately after alcohol administration and then again at days 2, 4, 7, 11, and 14 of the follow‐up period. PEth 16:0/20:4 levels were quantified by high‐performance liquid chromatography with tandem mass spectrometry detection. Results: (i) The increase in PEth 16:0/20:4 from baseline to maximum concentration was less than that of PEth 16:0/18:1 or PEth 16:0/18:2 homologs during the 6‐hour period after EtOH administration; (ii) the mean half‐life of PEth 16:0/20:4 was 2.1 ± 3 (SD) days, which was shorter than the mean half‐life of either PEth 16:0/18:1 or PEth 16:0/18:2, 7.6 ± 3 (SD) or 6.8 ± 4 (SD) days, respectively. Conclusions: The pharmacokinetics of PEth 16:0/20:4 in whole blood samples is detectable after alcohol consumption and differs in amount synthesized and rate of elimination versus PEth 16:0/18:1 and 16:0/18:2. Measuring the concentrations of these 3 homologs has the potential to provide more information about the amount and time frame of alcohol consumption than any one alone. Phosphatidylethanol (PEth) is a metabolite of alcohol used as a direct biomarker for alcohol consumption. We present for the first time the pharmacokinetics of the third most abundant PEth homolog, PEth 16:0/20:4, in whole human blood. Its rate of formation and half‐life of elimination, 2.1 days, differ from those of the more abundant PEth 16:0/18:1 and 16:0/18:2 homologs. The addition of this homolog will enhance the estimation of the amount, pattern, and time frame of recent alcohol consumption. [ABSTRACT FROM AUTHOR]