Markers of Alcohol Use

Abstract

Nowadays, hair analysis of alcohol biomarkers represents part of the routine workflow for many laboratories involved in clinical and forensic toxicology. In particular, ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs), namely ethyl myristate, ethyl palmitate (EtPa), ethyl oleate and ethyl stearate, have been extensively studied in the last 20 years, as potential markers for the diagnosis of repeated alcohol consumption. To date, a continuative consumption of 60 g of pure alcohol or above per day is considered a potentially hazardous drinking behaviour. Two different thresholds have been recently chosen by the Society of Hair Testing (SoHT) for both hEtG and EtPa; the lower cut-off (5.0 pg mg−1 for hEtG and 120 pg mg−1 for EtPa) aims to discriminate abstinence or occasional use from repeated alcohol consumption, while the higher concentration (30.0 pg mg−1 for hEtG and 350.0 pg mg−1 for EtPa) is suggested for the diagnosis of chronic excessive alcohol consumption. hEtG may be influenced by many factors, such as washout effects, cosmetic treatments, and pathological conditions, thus requiring an adequate interpretation. On the other hand hFAEEs are mainly affected by several hair products that lead to false positive results. Finally, cocaethylene (CE) is still a reliable marker of alcohol use among cocaine users.