Drugs in blood and urine samples from victims of suspected exposure to drink spiking: A prospective observational study from Oslo, Norway

People regularly contact emergency medicine services concerned that they have been exposed to drink spiking, i.e., exposure to drugs without their knowledge or permission. We identified drugs in blood and urine samples from patients suspecting exposure to drink spiking, with special consideration for drugs not reported taken by the patient (unreported drugs). From September 2018 to May 2019, we collected blood and urine samples from patients 16 years or older presenting at an emergency clinic in Oslo, Norway, within 48 hours of suspected exposure to drink spiking. We also collected information on ethanol ingestion and drugs taken. Blood samples were analyzed for 20 classical recreational drugs using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and an automated enzymatic method for ethanol. Urine samples were analyzed using immunoassay methods and a specific gas chromatography mass spectrometry (GCMS) method for gammahydroxybutyrate (GHB). From 100 included patients (median age 24 years, 62 females), we collected 100 blood samples and 72 urine samples. Median time since exposure was 5 hours. Unreported drugs were found in 15 patients. Unreported drugs in the blood samples were clonazepam in 3, methylenedioxymethamphetamine (MDMA) in 3, amphetamine in 2, tetrahydrocannabinol (THC) in 2, tramadol in 1, cocaine in 1, and methamphetamine in 1. Unreported drugs in the urine samples were cocaine in 5, amphetamine in 4, ecstasy in 3, and cannabis in 2. Ethanol was found in 69 patients, all reporting ethanol ingestion. Median blood ethanol concentration was higher in patients with no unreported drugs detected, 1.00‰ (interquartile range (IQR) 0-1.52) vs. 0‰ (IQR 0-0.46) (p