ANALYTICAL CHEMISTRY AT FORENSIC INSTITUTES 63 CHIMIA 2002, 56, No. 3

Chimia 56 (2002) 63–65 © Schweizerische Chemische Gesellschaft ISSN 0009–4293

Drugs and Driving: Analytical Strategy

Marc Augsburger*

Abstract: Consumption of psychoactive substances may impair driving performance. Because of the diversity of the substances, toxicologists have to develop analytical strategies which allow the detection and the quantification of drugs in biological samples. The analytical strategy described here is composed of three steps: screening, confirmation, and quantification. For screening, immunological tests and chromatography techniques (GC and HPLC) are often used. For confirmation, identification by means of mass spectrometry is required, and quantification is often realized through chromatographic techniques.

Keywords: Driving under the influence of drugs (DUID) · Forensics · Gas chromatography · Immunoassays · Liquid chromatography · Mass spectrometry

Introduction ton of Vaud, the same results were ob- these two situations. In order to help the served [2]. Moreover, methadone, which judge to demonstrate driving incapacity , Consumption of legal or illegal psycho- is frequently used as a heroin substitute in forensic analysis has to determine wheth- active substances has become very com- Switzerland for narcotic maintenance er the subject was under the influence of mon in our society, and an increase in the treatment of former opiate addicts, was drugs which could impair driving capaci- consumption of these substances can be never found as the sole drug present. The ty at the time of the event (police con- observed. On the other hand, road traffic high incidence of interaction for metha- trol, crash, ...). The only possibility to is increasing continuously. Because of done cases suggests that driving impair- find an answer through forensic analysis the extent of these two social phenomena, ment of patients under methadone-substi- is to quantify the drugs in the blood. In it is not surprising that driving under the tution treatment should be evaluated case of inaptitude, forensic analysis has influence of drugs is gaining in signifi- carefully considering that methadone to help the administration to evaluate the cance for the health, political, juridical, side effects could be increased by inter- dependence on certain drugs. In this con- and administrative authorities. It is well action with other drugs. The prevalence text, urine and hair are the matrices of known that the effects of alcohol can im- of drug use in combination with alcohol choice for the analysis because of their pair driving. Therefore, it seems justified is frequently reported in the different large window of detection. However, for to wonder if some crashes or aberrant at- studies included in the overall survey of alcohol, blood is widely used for labora- titudes could be explained by impairment the Council of Europe [1]. This survey tory diagnosis of chronic alcohol abuse due to consumption of psychoactive sub- emphasized also that higher accident risk by the determination of carbohydrate- stances such as cannabis, opiates, co- in the event of multiple drug use is a deficient transferrin (CDT) or other caine, amphetamines, benzodiazepines, reflection of the clear synergistic inter- markers [3]. LSD, or tranquilizers. action of alcohol and drugs, if mortality In most surveys reported in different is taken as the outcome variable. Conse- European countries cannabinoids are the quently, the analytical strategy set up for Substances most frequently detected illicit drugs [1]. the evaluation of the driving impairment In general the use of opiates is less fre- due to the consumption of drugs must As suggested by one group of the quently observed in driver populations screen a wide variety of drugs which are Council of Europe (Pompidou group) [1], than the use of cannabis. The most fre- suspected of decreasing driving perform- it seems unacceptable to base a reasoned quently detected licit drugs in all driver ance. argument about drugs and road safety on populations are the benzodiazepines. In a Impairment due to drug consumption an over-simplified distinction between survey concerning the nature of the drugs can be observed in two different situa- licit and illicit drugs. It is not the classi- used among drivers suspected of driving tions. On the one hand, impairment is due fication which matters, but the use to under the influence of drugs in the Can- to a single dose of drug. The effects of the which such substances are put. A lot of drug consumption involve transitional psychopharmacological studies have re- impairment of driving performance (in- vealed the adverse effects of many drugs *Correspondence: Dr. M. Augsburger capacity). On the other hand, impairment on driving performance. On the basis Institut Universitaire de Médecine Légale can also be due to chronic consumption of current knowledge, the psychotropic Laboratoire de Toxicologie Analytique of a drug, involving drug dependence. drugs which are capable of producing Rue du Bugnon 21 CH–1005 Lausanne In this case, driving performance is im- driving impairment are: anesthetics, Tel.: + 41 21 314 70 70 paired on a long-term basis (inaptitude). antidepressants, antihistamines, canna- Fax: + 41 21 314 70 90 E-Mail: [email protected] The analytical strategy is different in binoids, cardiovasculars, hallucinogens, ANALYTICAL CHEMISTRY AT FORENSIC INSTITUTES 64 CHIMIA 2002, 56, No. 3 hypnotics, narcotics, psychomimetics, sedatives, solvents, stimulants, and vola- Screenings tiles. The challenge for the analytical toxicologist is to develop a sensitive (immunoassays, GC-FID/NPD/MS, HPLC-DAD) screening which can be used for the
detection of the majority of these psycho- tropic drugs. In case of licit drug prescription, there Confirmation & identification is no doubt that some medications cause drowsiness for some patients. However, (GC-MS, HPLC-MS/DAD) drowsiness could be a desired therapeutic
goal without side-effects and depend upon the situation and the indication for Quantification which a drug is prescribed. If the patient wants to sleep during the night, drow- (GC-FID/NPD/ECD/MS, HPLC-MS/DAD/fluorescence) siness is a desired effect; but during day- time it could adversely affect the alert- Fig. Analytical strategy for biological sample analysis for the determination of driving impairment ness of a car driver. Moreover, it must be due to drug consumption. remembered that patients for whom a tranquilizer is prescribed to treat anxiety Saliva has been proposed as a speci- illicit drugs, to obtain a driving license or aggressiveness, or depressed patients men for roadside tests. However, the con- [5]. who take some antidepressants, are cer- centration of drug in the saliva specimen For fatally injured drivers it is recom- tainly safer drivers after they have re- will depend on the type of saliva, whether mended that blood be collected from the ceived their medication. it is true parotid saliva or not, on the pH femoral vein at autopsy, because in the of salivary flow, on salivary flow stimu- case of weakly basic drugs such as the tri- lation, and on the plasma protein binding cyclic antidepressants, concentrations in Matrices of the drug or metabolite. Under certain cardiac and sub-clavian blood increase conditions (e.g. standardized saliva col- after the death. Moreover, other speci- Analysis of blood, urine, saliva or hair lection, development of specific immu- mens such as gastric content, vitreous gives different information (Table 1). noassays for saliva) saliva will play an humor, liver or bile are available, and Blood has been considered to be the only important role for the recognition on the may complete information. suitable specimen. This is obviously true, road by the police of driving impairment because available pharmacological data due to drug consumption. An earlier use attempt to correlate plasma concentra- of saliva testing was conducted by Peel et Analytical Strategy and tions to either therapeutic or impairment al. (1984) [4]. Fifty-six saliva samples Analytical Tools effects. The detection of a drug and/or its from 445 suspected drivers were ana- metabolites in blood is evidence of recent lyzed for the presence of cannabinoids, Laboratories have often adopted an use and therefore of a potentially impair- volatiles and benzodiazepines using an analytical strategy composed of three ing effect. However, some drugs and immunoassay technique and GC/MS for steps (Fig.): their metabolites can be detected for ex- confirmation. The authors concluded that a) general unknown analysis in order to tended periods in blood after either acute the use of saliva was a potentially versa- determine the presence of drugs in the or chronic dosing. Urine is probably the tile noninvasive technique. samples; specimen of choice for additional infor- Although some techniques have been b) specific identification of the drugs; mation and hair analysis can represent a examined which test hair samples, the c) quantification of drugs in blood sam- powerful tool to estimate the historical consensus of opinion indicates that they ples and urine. aspect of the situation. Urine is preferred are not reliable due to the inconsistent re- Different analytical tools can be used for screening since drug concentrations lationship between results and recent for the first step. Methods for the deter- are usually higher and can be detected for drug ingestion. However, hair analysis is mination of the presence of drugs in the longer. However the use of blood sam- a highly effective and reliable tool for the samples are based on immunological ples may be more important with respect investigation of drug abuse behavior. tests, gas chromatography (GC) or liquid to the evaluation of driving performance This is very useful for checking the phys- chromatography (LC). Presence or ab- related to the drug. ical fitness of subjects, former users of sence of a urine sample influences the first step. In the presence of a urine sam- Table 1. Time period for drug detection in different matrices and relative information ple, screenings were essentially per- formed on the urine. In the absence of a Specimen Time period for detection Information urine sample, screenings were done an Blood about 1 d correlation with impairing effects blood. Because the aim of this step is to detect the presence of substances with Saliva about 1 d recent consumption of drug potential of producing driving impair- Urine about 2–4 d consumption of drug ment at therapeutic and toxic levels, im- munoassays and GC-MS analysis are Hair about 1 d to 6 mon drug consumption during a time period probably complementary methods. GC- depending of the length of the hair MS data can be automatically compared to mass spectrum libraries, such as the ANALYTICAL CHEMISTRY AT FORENSIC INSTITUTES 65 CHIMIA 2002, 56, No. 3

Table 2. Main toxicological results. Car crash. logical interactions between these sub- stances have to be considered, resulting Specimen Results in higher driving impairment. Blood free morphine (260 ng/ml), total morphine (2900 ng/ml), free codeine (80 ng/ml), total codeine (100 ng/ml), flunitrazepam (9 ng/ml), midazolam (65 ng/ml), Conclusion methaqualone (280 ng/ml) Driving is a task which can be Urine free morphine, total morphine, free codeine, total codeine, impaired by psychoactive substances. 6-monoacetyl-morphine, normorphine, norcodeine, cocaine, benzoylecgonine, When judges want to know whether a ecgonine methylester, ethylcocaine, ethylecgonine, THCCOOH, methaqualone, driver was under the influence of drug, metabolites of methaqualone, flunitrazepam, 7-aminoflunitrazepam, hydroxymidazolam, trimipramine, diphenhydramine, papaverine, metabolites the analytical strategy must include of papaverine, paracetamol, metabolite of paracetamol, nicotine, cotinine, screening of a huge diversity of psycho- caffeine active drugs. It is not sufficient to look for only a few substances. Blood has been considered to be the only suitable PMW database. During the second step, must be evaluated individually. More- specimen for identifying cases of driving the use of mass spectrometry (MS) is un- over, numerous studies support the dis- under the influence of drugs, even though doubtedly needed. Immunoassays cannot turbing fact that most drivers who test no concentration threshold beyond which be used to confirm immunoassays. MS is positive have more than one drug in their driving performance becomes impaired an important technique in the forensic blood. A drug-and-alcohol combination is given, as is the case for alcohol. The laboratory. Because it is possible to dif- is the most frequent, but the use of multi- analytical strategy developed for the ferentiate and identify substances, the use ple drugs is very common. This further evaluation of driving impairment due to of GC-MS has become the method of complicates the task of the analytical lab- the consumption of drugs is based on choice for confirming the presence of oratory, because procedures must be three steps: screening, confirmation, and drugs and their metabolites in blood. LC selective enough to identify each drug quantification. For a precise identifica- with diode array UV detection is some- and metabolite separately. tion of substances, mass spectrometry is times also appropriate. Recently, the use recommended and for quantification, dif- of LC-MS as a method for the screening ferent chromatographic techniques can of drugs in biological samples has been Example be used depending on the drug. proposed. LC- or GC-MS are also appro- Received: February 5, 2002 priate procedures for determining the On Sunday at 7 a.m. in a city, a concentrations of drugs and their meta- 24-year-old man lost control of his vehi- [1] ‘Pompidou Group, Road traffic and drugs’, bolites, in particular when deuterated cle. The car struck a lamp post. Police Council of Europe Publishing, Strasbourg, internal standards are available. Other noticed that the man did not walk straight 1999, 332 pp. methods are also suitable for quantifying and had coordination problems, although [2] M. Augsburger, L. Rivier, ‘Drugs and alco- drugs in biological samples. Depending the breathalyzer indicated no alcohol hol among suspected impaired drivers in on the drugs and their metabolites, LC consumption. The physician who took Canton de Vaud (Switzerland)’, For. Sci. Int. 1997, 85, 95–104. with UV or fluorescence detection and samples observed that the driver was [3] F. Musshoff, T. Daldrup, ‘Determination of GC with a nitrogen phosphorus detector clearly under the influence of drugs. The biological markers for alcohol abuse’, J. (NPD), electron capture detection (ECD) patient declared that he had drunk cham- Chromatogr. B 1998, 713, 245–264. or a flame ionization detector (FID) rep- pagne and that he had taken some pills of [4] H.W. Peel, B.J. Perrigo, N.Z. Mikhael, ‘De- resent appropriate techniques. Each of Rohypnol® (flunitrazepam). Analytical tection of drugs in saliva of impaired driv- these procedures requires either sample results (GC-MS/NPD/ECD) are given in ers’, J. For. Sci. 1984, 29, 185–189. preparation, extraction, or optimization Table 2. [5] F. Tagliaro, R. Valentini, G. Manetto, F. Crivellente, G. Carli, M. Marigo, ‘Hair anal- of chromatographic conditions. There- Toxicological findings confirmed the ysis by using radioimmunoassay, high-per- fore, these types of analysis should only consumption of flunitrazepam and alco- formance liquid chromatography and capil- be performed in laboratories with experi- hol. The alcohol consumption was indi- lary electrophoresis to investigate chronic ence in analytical toxicology. rectly confirmed through the presence of exposure to heroin, cocaine and/or ecstasy The introduction in the last twenty ethylcocaine and ethylecgonine, two me- in applicants for driving licenses’, For. Sci. years of many different immunoassays tabolites of cocaine. When cocaine and Int. 2000, 107, 121–128. and mass spectrometric procedures has alcohol are taken together, cocaine is par- [6] M.A. Peat, B.S. Finkle, ‘Toxicological as- say of psychoactive substances in biological permitted the detection, specific identifi- tially converted by a liver enzyme to its fluids’, in ‘Methodology in man-machine cation, and measurement of very low ethyl homologue called ethylcocaine [7]. interaction and epidemiology on drugs and concentrations of drugs (ng/ml). Unfor- The analysis also indicated the consump- traffic safety’, ARFI publication, Padova, tunately, as underlined by Peat and Fin- tion of other psychoactive substances Italy, 1992, 95–110. kle [6], the ability to interpret these con- such as heroin (confirmed by the pres- [7] F.K. Rafla, R.L. Epstein, ‘Identification of centrations in terms of cause and effect ence of 6-monoacetyl-morphine [8]), cocaine and its metabolites in human urine relationships and risk in the context of cocaine, cannabis, methaqualone, mida- in the presence of ethyl alcohol’, J. Analyt. highway safety lags far behind. An ade- zolam, and trimipramine. Quantitative Toxicol. 1979, 3, 59–63. [8] E.J. Cone, P. Welch, J.M. Mitchell. B.D. quate pharmacodynamic or pharmacoki- analysis of the blood indicated that the Paul, ‘Forensic drug testing for opiates: I. netic database does not exist for most driver was most probably under the influ- Detection of 6-acetylmorphine in urine as an drugs to allow for such an interpretation ence of opiates, flunitrazepam, and mida- indicator of recent heroin exposure; drug or prediction of effects in the context of zolam. These substances presented the and assay considerations and detection all known factors. Therefore, each case risk of driving impairment. Pharmaco- times’, J. Analyt. Toxicol. 1991, 15, 1–7.