Drugs in oral fluid in randomly selected drivers Olaf H. Drummer a, * , Dimitri Gerostamoulos a , Mark Chu a , Philip Swann b , Martin Boorman c , Ian Cairns c a Victorian Institute of Forensic Medicine, Department of Forensic Medicine, Monash University, 57-83 Kavanagh Street, Southbank 3006, Australia b VicRoads, Denmark Street, Kew 3101, Australia c Traffic Alcohol Section, Victoria Police, Australia Received 9 October 2006; received in revised form 1 March 2007; accepted 3 March 2007 Abstract There were 13,176 roadside drug tests performed in the first year of the random drug-testing program conducted in the state of Victoria. Drugs targeted in the testing were methamphetamines and D 9 -tetrahydrocannabinol (THC). On-site screening was conducted by the police using DrugWipe 1 , while the driver was still in the vehicle and if positive, a second test on collected oral fluid, using the Rapiscan 1 , was performed in a specially outfitted ‘‘drug bus’’ located adjacent to the testing area. Oral fluid on presumptive positive cases was sent to the laboratory for confirmation with limits of quantification of 5, 5, and 2 ng/mL for methamphetamine (MA), methylenedioxy-methamphetamine (MDMA), and THC, respectively. Recovery experiments conducted in the laboratory showed quantitative recovery of analytes from the collector. When oral fluid could not be collected, blood was taken from the driver and sent to the laboratory for confirmation. These roadside tests gave 313 positive cases following GC–MS confirmation. These comprised 269, 118, and 87 cases positive to MA, MDMA, and THC, respectively. The median oral concentrations (undiluted) of MA, MDMA, and THC was 1136, 2724, and 81 ng/mL. The overall drug positive rate was 2.4% of the screened population. This rate was highest in drivers of cars (2.8%). The average age of drivers detected with a positive drug reading was 28 years. Large vehicle (trucks over 4.5 t) drivers were older; on average at 38 years. Females accounted for 19% of all positives, although none of the positive truck drivers were female. There was one false positive to cannabis when the results of both on-site devices were considered and four to methamphetamines. Crown Copyright # 2007 Published by Elsevier Ireland Ltd. All rights reserved. Keywords: On-site drug testing; Oral fluid; Amphetamines; Cannabis; Random drug testing; Drivers; GC–MS confirmation 1. Introduction A number of jurisdictions around the world have adopted the use of oral fluid to detect the presence of drugs of abuse, particularly in relation to persons driving motor vehicles [1–7]. The intent has been to detect recent use of an illicit substance at a time when the driver may be at a higher road safety risk to the community. Blood concentrations of these drugs cannot easily be compared to oral fluid. On average the methamphetamine (MA) concentration in oral fluid is about eight times that of blood, but this will vary according to a number of factors. D 9 -Tetrahydro- cannabinol (THC) concentrations are more variable in oral fluid compared to blood and will derive more from leaching out of the tissues within the oral cavity than partitioning from the circulating blood [8]. Nevertheless pharmacokinetic studies have on average shown a reasonable correlation between oral fluid and blood concentrations [9–11]. Oral fluid concentrations of methamphetamine and THC have been reported to range up to about 1000 and 4000 ng/ml, respectively, following measured doses of these drugs [8]. Recent amendments to the road safety act in the state of Victoria gave police the authority to randomly test drivers for the presence of THC and MA. The purpose of this law was to provide police with an effective deterrence (to taking drugs and driving), similar to the random breath alcohol program that has been in operation in the state for 30 years. Two on-site screening devices, Securetec DrugWipe 1 , and the Cozart Rapiscan 1 were selected for use by the police in their on-site www.elsevier.com/locate/forsciint Forensic Science International 170 (2007) 105–110 * Corresponding author. Tel.: +61 3 9684 4334; fax: +61 3 9682 7353. E-mail address: olaf@vifm.org (O.H. Drummer). 0379-0738/$ – see front matter. Crown Copyright # 2007 Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.forsciint.2007.03.028