Oral Fluid and Drug Impairment: Pairing Toxicology with Drug Recognition Expert Observations

According to the Governors Highway Safety Association, drugs are detected more frequently in fatally injured drivers than alcohol. Due to the variety of drugs (prescribed and/or illicit) and their various physiological effects on the body, it is difficult for law enforcement to detect/prosecute drug impairment. While blood and urine are typical biological specimens used to test for drugs, oral fluid is an attractive alternative matrix. Drugs are incorporated into oral fluid by oral contamination (chewing or smoking) or from the bloodstream. Oral fluid is non-invasive and easy to collect without the need for a trained professional to obtain the sample, unlike urine or blood. This study analyzes paired oral fluid and urine with drug recognition expert (DRE) observations. Authentic oral fluid samples (n = 20) were collected via Quantisal™ devices from arrestees under an institutional review board-approved protocol. Urine samples (n = 18) were collected with EZ-SCREEN® cups that presumptively screened for Δ9-tetrahydrocannabinol (cannabinoids), opiates, methamphetamine, cocaine, methadone, phencyclidine, amphetamine, benzodiazepines and oxycodone. Impairment observations (n = 18) were recorded from officers undergoing DRE certification. Oral fluid samples were screened using an Agilent Technologies 1290 Infinity liquid chromatograph (LC) coupled to an Agilent Technologies 6530 Accurate Mass Time-of-Flight mass spectrometer (MS). Personal compound and database libraries were produced in-house containing 64 drugs of abuse. An Agilent 1290 Infinity LC system equipped with an Agilent 6470 Triple Quadrupole MS was used for quantification of buprenorphine, heroin markers (6-acetylmorphine, morphine) and synthetic opioids. Subjects were 23–54 years old; 11 (55%) were male and 9 (45%) were female. Evaluator opinion of drug class was confirmed in oral fluid 90% of time and in urine 85% of the time in reference to scope of testing by the LC–MS methods employed (excludes cannabis and central nervous system depressants). Data indicate that oral fluid may be a viable source for confirming driving under the influence of drugs.