5-hydroxytryptophol as a marker for recent alcohol intake.
OBJECTIVE
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.
Department of Medicine, Division of Clinical Pharmacology, Karolinska Hospital, Stockholm, Sweden. olof.beck@ks.se
Olof
O
Beck
Anders
A
Helander
D006916:5-Hydroxytryptophan / Q000652:urine*; D000428:Alcohol Drinking / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans
D015415:Biomarkers; D006916:5-Hydroxytryptophan