J. Michael Walsh

Drugs and driving

The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence—which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for future research to better define prevalence and epidemiology; (2) Effects of Medicinal and Illegal Drugs on Driving Performance—focuses on the six classes of drugs most often found in impaired and injured drivers, draws conclusions regarding the risk of these drugs to traffic safety and discusses the need for additional research; (3) Toxicological Issues—discusses ways to identify drug users via behavioral testing and analytical techniques, reviews the approaches used by different countries, screening and confirmation techniques, alternative specimens (e.g., urine, oral fluid, sweat), and how rapid roadside testing could be coupled with behavioral and laboratory testing in an effective approach to identifying and prosecuting drugged drivers; (4) Driving Under the Influence of Drugs [DUID] Laws—provides an overview of DUID laws in the United States and Europe, discusses the basic tenets of these laws, the various types of DUID statutes, the reasons why many existing laws hinder the prosecution of drugged drivers and the rationale for developing per se legislation as a strategy to more effectively manage the drugged driver problem.

THE PREVALENCE OF DRUGS AND ALCOHOL IN FATALLY INJURED TRUCK DRIVERS

To assess the impact of alcohol and other drug use in the trucking industry, the National Transportation Safety Board, in collaboration with The National Institute on Drug Abuse investigated fatal-to-the-driver trucking accidents in eight states over a one year period. Comprehensive drug screens were performed on blood specimens collected from 168 fatally injured drivers. One or more drugs were detected in 67% of the drivers and 33% of the drivers had detectable blood concentrations of psychoactive drugs or alcohol. The most prevalent drugs were cannabinoids and ethanol, each found in 13% of the drivers. Cocaine or benzoylecgonine was found in 8% of the cases. Seven percent of the drivers blood specimens contained amphetamine or methamphetamine and 7% contained phenylpropanolamine, ephedrine, or pseudoephedrine. A panel of toxicologists reviewed the accident investigation report and the toxicology findings for each case and determined that impairment due to marijuana use was a factor in all cases where the delta-9-tetrahydrocannabinol concentration exceeded 1.0 ng/mL and that alcohol impairment contributed to all accidents where the blood alcohol concentration was 0.04% wt/vol or greater. In 50 of 56 cases where psychoactive drugs or alcohol were found, impairment due to substance use contributed to the fatal accident.

EPIDEMIOLOGY OF ALCOHOL AND OTHER DRUG USE AMONG MOTOR VEHICLE CRASH VICTIMS ADMITTED TO A TRAUMA CENTER

The objectives of this research were to (1) determine the incidence and prevalence of alcohol and other drug use among motor vehicle crash (MVC) victims admitted to a regional Level-I trauma center, and (2) to examine the utility of using a rapid point-of-collection (POC) drug-testing device to identify MVC patients with drug involvement. Blood and urine specimens were routinely collected per clinical protocol for each MVC victim at the time of admission. Blood alcohol concentration (BAC) levels were determined per standard clinical protocol. Clinical urine specimens were routinely split so that a POC drug-testing device for the detection of commonly abused drugs (Marijuana, Cocaine, Amphetamines, Methamphetamines, and Opiates) could be compared to that of the standard hospital laboratory analysis of each urine specimen (which also included Barbiturates and Benzodiazepines). In the six-month period of this study, nearly two-thirds of trauma center admissions were victims of motor vehicle crashes. During this time, blood and urine was collected from 322 MVC victims. Toxicology results indicated that 59.3% of MVC victims tested positive for either commonly abused drugs or alcohol. More patients tested positive for drug use than tested positive for alcohol, with 33.5% testing positive for drug use only, 15.8% testing positive for alcohol use only, and 9.9% testing positive for both drugs and alcohol. Less than half (45.2%) of the substance-abusing patients in this study would have been identified by an alcohol test alone. After alcohol, marijuana and benzodiazepines were the most frequently detected drugs. Point of collection (POC) test results correlated well with laboratory results and provide important information to initiate rapid intervention/treatment for substance use problems among injured patients.

The Need for Drugged Driving Per Se Laws: A Commentary

Objective: Triggered by the new federal commitment announced by the Office of National Drug Control Policy (ONCDP) to encourage states to enact drugged driving per se laws, this article reviews the reasons to establish such laws and the issues that may arise when trying to enforce them. Methods: A review of the state of drunk driving per se laws and their implications for drugged driving is presented, with a review of impaired driving enforcement procedures and drug testing technology. Results: Currently, enforcement of drugged driving laws is an adjunct to the enforcement of laws regarding alcohol impairment. Drivers are apprehended when showing signs of alcohol intoxication and only in the relatively few cases where the blood alcohol concentration of the arrested driver does not account for the observed behavior is the possibility of drug impairment pursued. In most states, the term impaired driving covers both alcohol and drug impairment; thus, driver conviction records may not distinguish between the two different sources of impairment. As a result, enforcement statistics do not reflect the prevalence of drugged driving. Conclusions: Based on the analysis presented, this article recommends a number of steps that can be taken to evaluate current drugged driving enforcement procedures and to move toward the enactment of drug per se laws.

Use of alcohol and drugs by Norwegian employees: a pilot study using questionnaires and analysis of oral fluid

BackgroundThe use of alcohol and drugs may affect workplace safety and productivity. Little is known about the magnitude of this problem in Norway.MethodsEmployee recruitment methods with or without individual follow-up were compared. The employees filled in a questionnaire and provided a sample of oral fluid. Samples were analysed for alcohol, ethyl glucuronide (EtG; a biological marker of recent large alcohol intake), psychoactive medicinal drugs and illegal drugs.ResultsParticipation rates with and without individual follow-up were 96% and 68%, respectively. Alcohol was negative (≤0.1 mg/ml) in all samples, but 21.0% reported the intake of alcohol during the last 24 h. EtG was positive (>2.2 ng/ml) in 2.1% of the samples. In-efficiency or hangover at work during the past year was reported by 24.3%, while 6.2% had been absent from work due to the use of alcohol. The combination of self-report and analytical testing indicated that medicinal or illegal drugs had been used during the last 48 h by 5.1% and 1.7% of the participants, respectively; while only 4.2% and 0.4% admitted the use in the questionnaire.ConclusionsSelf-reported data suggest that hangover after drinking alcohol appears to be the largest substance abuse problem at Norwegian workplaces, resulting in absence and inefficiency at work. Analysis of oral fluid revealed that the use of illegal drugs was more common than drinking alcohol before working or at the workplace. The analysis of oral fluid may be a valuable tool in obtaining additional information on alcohol and drug use compared to using questionnaires alone.

Relationships between urinalysis testing for substance use, medical expenditures, and the occurrence of injuries at a large manufacturing firm

Drug use among employees continues to be a serious concern for American employers. Over 80% of the large employers in the United States use some form of testing to detect drug use, but this practice is controversial and the cost-effectiveness of drug testing remains largely unknown. This study begins an empirical investigation of the consequences of drug testing by estimating its impact on medical care expenditures and injury rates at a large manufacturing firm in 1996–1999. Multiple regression analyses of a pooled cross-sectional time-series data set were used to separate the impact of drug testing from other factors and to help find the optimal level of testing that was associated with minimum medical expenditures. Results indicated that medical expenditures would be minimized when 42% of the employees in a calendar quarter were drug tested. This implies that, on average, employees should be tested 1.68 times a year. The results also indicated that doubling the testing rate would reduce the odds of incurring any injuries on the job by over half, but the injury rate was already so low that this impact was very small. Hopefully the results of this study will inform the policy debate over drug testing by focusing on real data, as opposed to supposition or political considerations that seem to dominate many discussions.

Is THC-COOH a Useful Determinant for Passive Inhalation in Oral Fluid THC Testing?

To the Editor: Many studies have demonstrated that passive exposure to marijuana smoke can lead to detectable concentrations of tetrahydrocannabinol (THC) in oral fluid (OF) (1 –3). It is reasonable to assume that subjects breathing air heavily laden with THC will absorb some of the drug. An important related issue is how long concentrations will remain detectable. The magnitude of the exposure depends greatly on many variables, including the duration of exposure, the potency of the marijuana being smoked, and the concentration of smoke in the enclosed space (i.e., room size, number of smokers and number of passive inhalers). Peak concentrations in OF have generally been observed at the end of exposure followed by a rapid decline typically within one hour (1, 2). Recently, Moore et al. (3) found that although THC was present in the OF sampled from the passively exposed subjects, no THC carboxy acid metabolite (THC-COOH) was detected at a cutoff of 2 pg/mL. The authors concluded that THC-COOH is likely to be a valid marker for active marijuana use, and recommended that “in order to avoid false positive oral fluid results assigned to marijuana use, by analyzing for only THC, the metabolite THC-COOH should also be monitored.” In our view, two key issues for workplace drug testing programs are raised by this research. First is the question of the validity of THC-COOH as a unique marker of cannabis use. We believe that for a marker to be useable, it must be scientifically validated that the marker occurs only in the “true” condition (characterized by such variables as dose response, time course of appearance and disappearance, and potential interferences (false positives) and does not occur in the “false” condition (no active use). It is well known that THC-COOH reaches peak concentrations in plasma at 0.5 to 4 hours and in urine at 8 to 14 hours, thus indicating a delay or lag time necessary for THC to be metabolized to THC-COOH in the liver, released into the blood and excreted in body fluids. Therefore, THC-COOH may have been present in the passively exposed subjects’ OF at times not sampled in previous studies. Second, for drug testing program policy makers, a major question is how likely it is that an individual would get sufficient passive exposure to test positive at some later time. At present, it remains unclear how long detectable levels of THC persist after the exposure ends. The answer to this question needs to be explored scientifically by evaluating dose-response,

The Science and Politics of Drug Testing in the USA

Over the last 14 years “employee drug testing” has become common business practice in the American workplace. A recent survey conducted by the American Management Association (1) [the 7th annual survey on “Workplace Drug Testing and Drug Abuse Policies” (Jan. 1993)] indicates nearly 85% of surveyed firms test employees for drugs. Since 1987, the date of the AMA’s initial survey, company drug testing in the United States has increased by 300%. It is estimated that more than 25 million American workers will be tested for illicit drugs this year.