W.K.Jeffery, Toxicology Section, RCMP Forensic Laboratory, Vancouver, British ColumbiaK.W.Hindmarsh,* Faculty of Pharmacy, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 P.W.Mullen, Kemic Bioresearch Laboratories, Kentville, Nova Scotia* To whom inquiries should be sent.

ABSTRACT: A drugs and driving database, maintained by the Drugs and Driving Committee of the Canadian Society of Forensic Science, includes case data collected from 11 Forensic Laboratories across Canada. The data presented herein are from 1158 submitted cases. The major drug classifications reported for impaired driving and fatal motor vehicle accidents are benzodiazepines, cannabis, stimulants, opioids and the barbiturates. The most frequently reported drug in each group was diazepam, THC, cocaine, codeine and butalbital, respectively. Alcohol was also detected in many of these cases.

INTRODUCTION: The Drugs and Driving Committee of the Canadian Society of Forensic Science was established in 1987 with a mandate to determine the extent of drug impaired driving in Canada and to explore the scientific and technical issues relating to the detection of drug impaired driving and the enforcement of drug impaired driving offenses. Data collection consisting of cases received from various Canadian Forensic Laboratories was begun and the initial findings were the subject of a report published in 1990.(1) This report was the first to supplement limited Canadian data previously reported.(2-4)

The present report provides an update of the results received from laboratories throughout Canada as of November 12, 1994. The focus is of the study is on drugs other than alcohol. Of the total 1158 cases submitted, impaired driving cases predominated (767). The remaining (391) cases were reported fatalities.

METHODS: The following laboratories participated in the study: the Forensic Laboratory Vancouver and the City Analyst Laboratory (British Columbia), the Forensic Laboratory Edmonton and the Coroners Laboratory in Edmonton (Alberta), the Forensic Laboratory Regina (Saskatchewan), the Forensic Laboratory Winnipeg (Manitoba), the Centre of Forensic Sciences and the Central Forensic Laboratory (Ontario), the Laboratoire de Police Scientifique (Quebec) and the Forensic Laboratory Halifax and Forensic Laboratory Sackville (Atlantic provinces). Standardized data collection sheets were used by the laboratories to submit their cases findings, on a quarterly basis. The cases were then entered into a computer program which enabled easy recovery for data analyzes. The data presented is the actual incidences of detection of the drugs and their metabolites.

RESULTS AND DISCUSSION: In this study, impaired driving cases typically represent those in which police have laid charges and where the blood alcohol concentration is below 100 milligrams per 100 milliliters (mg/100mL) (246 cases), or cases in which no alcohol is evident (375 cases, Table 1) although, this report includes 146 cases in which the alcohol concentration exceeds 100 mg/100 ml (mg%). As previously reported (1), the blood alcohol concentration (BAC) is a limiting factor since forensic laboratories in Canada do not normally analyze blood for drugs when the BAC is known to exceed 100 mg%. In addition, the number of cases where drugs were screened and not found was not reported. Thus, the Canadian drugs and driving database is not comprehensive, and in situations of impaired driving cases is usually limited to those cases with a zero or a low BAC. Fatality cases include all those where drugs were found, regardless of BAC (Table 1).

The impaired driving cases and the fatal driving incidences varied amongst provinces/regions (Table 2). Alcohol, along with other drugs, was detected in 580 cases. Blood alcohol concentrations were reported as being less than or greater than 100 milligrams per 100 milliliters (Table 1). The major drug types encountered, excluding alcohol, were the benzodiazepines (50.9%), cannabinoids (47.6%), stimulants (19.3%; e.g. cocaine), opioids (15.2%) and barbiturates (11.3%) (Table 3). Other drugs classifications included antidepressants, antihistamines, miscellaneous (e.g. acetaminophen, caffeine, quinine, chloroquine, cyanide, disulfiram, metoclopramide), volatiles (e.g. toluene), CNS depressants, anticonvulsants, cardiac medications, antipsychotics, hallucinogens, anti-inflammatory drugs, antiparkinsonism agents and, anticholinergics (e.g. atropine, hyoscyamine). Alcohol was detected in the majority of Cannabis cases (Table 4). The most commonly reported benzodiazepines (number of reported cases) were diazepam (208), nordiazepam (174), lorazepam (44), and triazolam (43). The most common stimulants were cocaine (133) and its major metabolite, benzoylecognine (71) (Table 5). The most frequently reported opioids were codeine (86) and meperidine (27). Butalbital (70) and phenobarbital(18) were the most frequently found barbiturate drugs. Amitriptyline (17) was the most prevalent antidepressant.

While the current study shows an incidence of alcohol in operators of vehicles similar to that reported in the United States (51.5%) (5), the reported incidence of Cannabis (6.7%), cocaine (5.3%) and benzodiazepines (2.9%) was reported as being considerably lower. The dissimilarity between the US and Canadian findings may simply reflect methodological differences in case data collection. In the American study, drug free and alcohol alone studies were included in the analyzes. If these cases were deleted, the incidence of Cannabis would increase to 37.6%, cocaine to 29.8% and benzodiazepines to 16.3%. However, even with these adjustments an appreciable difference is seen for benzodiazepine detection. Both studies found alcohol in combination with other drugs, suggesting the importance of follow up research on the indications of alcohol-drug additive effect, especially for those drugs known to have central nervous system effects. In contrast, a recent study from Norway reported that the most frequently detected drugs in blood samples from Norwegian drivers were the benzodiazepines (40%) and tetrahydrocannabinol (41%) (6) - results similar to those presented herein (Table 3). Brook off et al (7) conducted a consecutive-sample study (urine) on subjects arrested for reckless driving in 1993. Eighty-five percent of those considered to be clinically intoxicated tested positive for cocaine or marijuana. They also noted that nearly half of the drivers intoxicated with cocaine performed normally on standard sobriety tests. Therefore, standard sobriety testing (SST) does not always indicate drug ingestion, suggesting drug analyzes may be an useful adjunct to SST.

With the exception of barbiturates, alcohol was also involved in greater than 50% of the most frequently detected drugs in impaired driving cases (Table 5): benzodiazepines, 51.2%; Cannabis, 51.2%; stimulants, 58.3%; opioids, 56.7%; barbiturates 18.3%. The relatively low incidence of alcohol in combination with barbiturates may be partially due to the education process that has been in place over the past 30 years emphasizing the synergistic effect of barbiturates and alcohol, in addition to, a decrease in the prescribing of barbiturates.

While education related to drugs and driving seems like a mammoth undertaking, the evidence from this study clearly indicates that only a few major drugs are involved. It is hoped that these findings will serve as an impetus for further forensic analytical data collection and research in the drugs and driving context and renewed drug education efforts for both law enforcement personnel (such as the "Drug Recognition Expert" program currently being assessed in British Columbia) and the general (driving) public.

CONCLUSIONS AND COMMENTS: The most common drugs associated with impaired driving and fatal motor vehicle investigations in Canada, with the exception of alcohol, are benzodiazepines, Cannabis, stimulants, opioids and barbiturates. Alcohol is frequently found in combination with these drugs. The involvement of drugs in driving is possibly a significant factor adversely affecting highway safety and consequently should be of major concern to all Canadians. This study indicates that there are but a few major drugs which should be targeted for drug education purposes, namely diazepam, Cannabis, cocaine, codeine and butalbital.

ACKNOWLEDGMENTS: The authors and the Drugs and Driving Committee wish to acknowledge the assistance received from the participating forensic laboratories throughout Canada, the Federal Department of Justice for financial assistance and Dr. D. Jeffery for data entry.

REFERENCES: 1. Peel, H.W. and Jeffery, W.K. "A Report on the Incidence of Drugs and Driving in Canada". Can. Soc. Forens. Sci.J., Vol. 23; 75-79, 1990.

2.Cimbura, G., Lucas, D.M., Bennett, R.C., Warren, R.A. and Simpson H.M., "Incidence and Toxicological Aspects of Drugs Detected in 484 Fatally Injured Drivers and Pedestrians in Ontario". Journal of Forensic Sciences, Vol. 27; 855-867, 1982.

3. Donelson, A.C., Cimbura, G., Bennett, R.C. and Lucas, D.M., "The Ontario Monitoring Project: Cannabis and Alcohol Use Among Drivers and Pedestrians Fatally Injured in Motor Vehicle Accidents from March 1982 through July 1984". Report from the Traffic Injury Research Foundation of Canada, Ottawa, 1985.

4. Peel, H.W., Perrigo, B.J. and Mikhael, N.Z., "Detection of Drugs in Saliva of Impaired Drivers". Journal of Forensic Sciences. Vol. 29, 185-189, 1984.

5. Terhune, K.W., Ippolito, C.A., Hendricks, D.L. et al, "The Incidence and Role of Drugs in Fatally Injured Drivers". Report of the U.S. Department of Transportation, National Highway Traffic Safety Administration, October 1992 (report DOT HS 808 065).

6. Christophersen, A.S., Gjerde, H. and Morland, J., "Benzodiazepines, Tetrahydrocannabinol and Drugged Driving in Norway". Alcohol, Drugs and Traffic Safety - T'92, Vol.2.pp 1082-87. (Proceedings of the 12th International Conference on Alcohol, Drugs and Traffic Safety, Cologne, 28 Sept - 2 Oct, 1992).

7. Brook off, D., Cook, C.S., Williams, C. and Mann C.S., "Testing Reckless Drivers for Cocaine and Marijuana". N. Engl.J.Med., Vol 331(8); 518-22, 1994.