Phosphatidylethanol (PEth) is a whole blood marker of alcohol alcohol that can be detectable for up to one month after alcohol consumption.
Testing for PEth can be performed using dried blood spots or whole blood.
It is detectable within one hour of alcohol consumption, peaks at eight hours and is detectable for 3 to 12 days after consumption with the main half-life of three days.
Phosphatidylethanol (PEth) is a direct and specific biomarker of alcohol consumption.
It is formed in the body when ethanol reacts with phosphatidylcholine, a common phospholipid in cell membranes, through the enzyme phospholipase D.
PEth testing is often used in clinical and forensic settings to monitor alcohol consumption and adherence to alcohol abstinence programs.
A PEth concentration less than 20 ng/mL in indicates minimal or no recent alcohol consumption and the concentration of greater than 200 ng/mL correlates with heavy alcohol consumption of four or more standard drinks daily.
PEth formation and degradation is unaffected by age, sex, or organ dysfunctions.
The rate of its formation depends on the level and activity of phospholipase D, which varies among individuals, and degradation also varies with an estimated half-life of 4 to 10 days.
PEth may be detectable up to five weeks after heavy alcohol consumption and blood levels increase with higher quantity and frequency of alcohol consumption and decreases with time lapsed since the last ingestion of alcohol.
False low levels may occur in patients with low haptoglobin levels consistent with intravascular hemolysis.
PEth has a sensitivity of 95 to 99% and a specificity of 100% for high levels of alcohol consumption.