Ethyl Glucuronide Excretion in Humans Following Oral Administration of and Dermal Exposure to Ethanol

Abstract

Ethyl glucuronide (EtG) is a direct ethanol biomarker and U.S. Department of Health and Human Services has advised that specificity studies at low EtG levels are needed for distinction of ethanol consumption and incidental exposure. The authors report urinary EtG excretion with ethanol abstinence, dermal exposure and oral consumption. EtG concentration by sensitive liquid chromatography-tandem mass spectrometry measurement in 39 urine specimens from adult alcohol abstainers (< 10-62 microg/L) and in urine from 13 children (< 10-80 microg/L) indicates either unrecognized ethanol exposure or endogenous ethanol metabolism. With repetitive daily dermal exposure to hand sanitizer (60% ethanol) by 9 adults, EtG concentration ranged from < 10 to 114 microg/L in 88 first-morning void specimens. EtG excretion following a 24 g ethanol drink by 4 adults revealed maximum urine EtG concentration (12,200-83,200 microg/L) at 3 to 8 h postdose and an EtG detection window up to 25-39 h, compared to an ethanol window of only 2 to 4 h. Oral ethanol use also showed an increase in the percent (molar equivalent) ethanol excreted as EtG with increasing oral ethanol doses. Human excretion studies show 1. EtG detectable at low concentration (< 100 microg/L) when ethanol use or exposures is not evident, 2. EtG concentration less than 120 microg/L in first morning specimens from adults with repeated dermal exposure to ethanol, 3. EtG levels maximally elevated within 3-8 h and above baseline for up to 39 h after a 24 g ethanol drink, and 4. a dose-dependent increase in the percentage of ethanol excreted as EtG with increasing oral ethanol use.

A study of ethyl glucuronide in post-mortem blood as a marker of ante-mortem ingestion of alcohol

“…In humans, this should be studied by administering different doses and collecting all urine voided until the end of EtG elimination. One study administered 3-25 g of ethanol to 4 subjects, and showed a dose-response relationship, with a larger % of the ethanol excreted as EtG at higher doses (56). When comparing this to our results (paper IV) and those by Dahl et al (49), where larger doses were ingested, this further strengthens the picture of a dose-response curve.…”

“…ADH is saturated at approximately 0.2 g/L ethanol, and this is in accordance with the findings of glucuronidation, which showed increasing activity after ingestion of doses higher than 0.15 g/kg, resulting in blood alcohol concentrations around 0.2 g/L (56). An alternative explanation is the lower bioavailability of ethanol when ingested in low doses.…”

Determination of ethyl glucuronide in human serum by capillary zone electrophoresis and an immunoassay

“…However, in order to avoid false-positive results such as those obtained with a metabolite of chloral hydrate [25], the confirmation of EtG-positive results should be confirmed with another method. Furthermore, for the analysis of EtG in urine, true false-positive results of EtG were demonstrated in urine after use of mouthwash [18] and contact with hand sanitizer [28,42] containing ethanol. With the 13 blank serum samples mentioned above, EtG was not detected by CZE, and EIA provided very low EtG levels.…”

Diagnostic Accuracy and Interpretation of Urine Drug Testing for Pain Patients: An Evidence-Based Approach

“…For doctors to understand UDT ethanol results, it is essential that they understand ethanol metabolism and the formation of the ethanol byproducts ethyl glucuronide and ethyl sulfate Crews et al, 2011b;Dahl et al, 2002;Helander & Beck, 2005;Helander et al, 1996;Rosano & Lin, 2008;Schmitt et al, 1997;Stephanson et al, 2002;Wojcik & Hawthorne, 2007;Wurst et al, 2006;Wurst et al, 2004). This is because false positive ethanol results can result from fermentation of glucose from diabetic patient samples .…”