Abstract
BACKGROUND AND OBJECTIVES: Ketamine is a psychoactive substance used for its stimulant and hallucinogenic properties. As the use of ketamine may lead to impaired driving, we aimed to assess the occurrence of ketamine in the driving population tested positive for narcotics in roadside checks using oral fluid analysis. Oral fluid concentrations of ketamine and norketamine were examined to determine the percentage of drivers susceptible to ketamine impairment. METHODS: A retrospective descriptive study was conducted over a 32-month period in 2020-2023 on drivers who tested positive to the DrugWipe®5S saliva test in our region of northeastern France. Mass spectrometry was used to confirm the DrugWipe®5S result and to determine oral fluid concentrations of ketamine and norketamine. RESULTS: During the entire study period, 3364 drivers were tested positive at the roadside using the DrugWipe®5S rapid test. After mass spectrometry, 3043 drivers were finally confirmed as true positives. Ketamine was detected in 88 drivers who were 80.7% male, 95.4% polydrug users and were 27.5 ± 7.1 years old, representing 2.6% of the total driver population. Ketamine concentrations were 821 ± 2264 and 7.8 ± 12.3 ng/mL in the presence and absence of norketamine, respectively. Finally, 26.1% of the ketamine-positive drivers had a ketamine oral fluid concentration potentially associated with impaired driving. CONCLUSION: Ketamine and norketamine should be added to the list of drugs to be tested in oral fluid for driving under the influence of drugs. Besides blood or urine, oral fluid could be an interesting alternative biological matrix for addiction medicine.