URINARY 5-HYDROXYTRYPTOPHOL FOLLOWING ACUTE ETHANOL-CONSUMPTION - CLINICAL-EVALUATION AND POTENTIAL AVIATION APPLICATIONS

Hypothesis: The unknown prevalence of alcohol use and misuse among avi ation pilots, crewmembers and associated support personnel call for co ntinuous improvement of methods for detecting recent alcohol use. Earl y detection is essential to proper treatment and prevention of potenti ally catastrophic mishaps. Urinary 5-hydroxytryptophol (5HTOL), a sero tonin (5HT) metabolite, has shown promise in the clinical setting as a noninvasive marker of recent alcohol consumption. Methods: The urinar y 5HTOL concentrations of 11 male and female subjects were followed fo r approximately 24 h following dosing with ethanol 0.6 g . kg(-1). Con centrations were reported as a ratio of 5HTOL to 5-hydroxy-indoleaceti c acid (5HIAA), 5HTOL/5HIAA (pmol/nmol), to compensate for urinary dil ution and elevated 5HTOL levels due to dietary intake. Data from one m ale subject was excluded after he admitted to continued alcohol consum ption subsequent to dosing and missing several urine samples. Results: 5HTOL/5HIAA ratios remained above the 15 pmol/nmol cutoff for recent alcohol use for approximately 11-16 h in all except one subject. Calcu lations based on body weight and administered alcohol dose suggest tha t measurable blood alcohol levels would exist for only 5-7 h post inge stion. Conclusion: This study confirmed the extended elevation of 5HTO L/5HIAA ratios observed in earlier studies, even at the relatively low alcohol dose used herein. 5HTOL appears to be a marker for acute alco hol consumption worthy of further investigation by military and civili an aviation authorities. Potential aviation applications of 5HTOL incl ude validation of measurable blood alcohol concentrations, investigati on of poor performance due to hangover effects, and as a forensic toxi cology tool in aircraft accident investigations to distinguish between actual alcohol ingestion and post-mortem alcohol synthesis.