5‐Hydroxytryptophol as a marker for recent alcohol intake

Publisher Website
Google Scholar
Abstract
Aims  To review the mechanism behind the alcohol‐induced shift in serotonin metabolism, and the use of urinary 5‐hydroxytryptophol (5‐HTOL) as a biochemical marker of acute alcohol consumption.Background  The serotonin metabolite 5‐HTOL is a normal, minor constituent of urine and is excreted mainly in conjugated form with glucuronic acid. The formation of 5‐HTOL increases dramatically after alcohol intake, due to a metabolic interaction, and the elevated urinary excretion remains for some time (>5–15 hours depending on dose) after ethanol has been eliminated. This biochemical effect can be used for detection of recent alcohol intake.Results  5‐HTOL is determined by the gas chromatography‐mass spectrometry (GC‐MS) or liquid chromatography and mass spectrometry (LC‐MS) techniques. A new ELISA method for 5‐HTOL glucuronide provides a promising clinical assay. The most robust way to use the marker is by measuring the ratio of 5‐HTOL to 5‐hydroxyindoleacetic acid, because this compensates for urine dilution and dietary intake of serotonin. 5‐HTOL is a very sensitive and specific indicator of recent alcohol consumption and, as such, a valuable complement to self‐report. In clinical use, 5‐HTOL is effective for monitoring lapses into drinking during out‐patient treatment and for objective evaluation of treatment efforts. Other applications include detection of high‐risk patients in elective surgery, monitoring of disulfiram treatment and a method to rule out artefactual ethanol formation in forensic toxicology. 5‐HTOL can also be used as a sensitive reference method for validation of self‐report data in clinical alcohol research.Conclusions  An elevated urinary 5‐HTOL level can serve as a sensitive and reliable marker for recent alcohol intake with a number of clinical and forensic applications.