In recent years, the interest in the use of oral fluid as biological matrix has increased significantly, particularly for detecting driving under the influence of drugs (DUID). In this study, the relationship between the oral fluid and blood concentrations of drugs of abuse in drivers suspected of DUID is Nevertheless the data reflect the variability of the OF/B ratios in drivers under the influence of drugs.The wide range of the ratios, however, does not allow reliable calculation of the blood concentrations from oral fluid concentrations.

In Belgium, the driving under the influence of drugs (DUID) procedure consists of three steps: observation of external signs of drug consumption by a police officer; an on-site urine test for amphetamines, cannabinoids, cocaine, and opiates; and blood sampling by a physician for gas chromatography-mass spectrometry analysis. The driver is sanctioned if THC is greater than 2 ng/mL, morphine is greater than 20 ng/mL, or amphetamine, methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine, N-methyl-1-(3.4-methylenedioxyphenyl)-2-butanamine, cocaine, or benzoylecgonine are greater than 50 ng/mL in plasma. We analyzed the results of 450 blood samples taken from May 2000 to February 2005. Cannabis was most often found above the cut-off (73.5% of the cases), followed by MDMA (20.4%), amphetamine (19.8%), benzoylecgonine (17.9%), cocaine (6.9%), and morphine (2.7%). One drug was found in 72.0% of the cases, two drugs in 22.6%, three drugs in 5.2%, and four drugs in 0.25%. In 10.7% of the plasma samples no target drugs were found above the legal cut-off. This percentage was 8.4% when urine was obtained and tested on-site and 21.2% when no urine was obtained (chi2 = 8.574, P = 0.0034). In 64.6% of these samples, a target drug (THC in 74.2%) was found under the legal cut-off. These data indicate that roadside urine testing significantly decreases the number of unnecessary blood analyses in DUID.

No abstract

The role of angiotensin converting enzyme (ACE, peptidyl dipeptidase A) in metamorphic- and reproductive-related events in the Egyptian cotton leafworm, Spodoptera littoralis (Lepidoptera, Noctuidae) was studied by using the selective ACE inhibitor captopril. Although oral administration of captopril had no effect on larval growth, topical administration to new pupae resulted in a large decrease of successful adult formation. Oviposition and overall appearance of adults emerging from treated larvae did not differ significantly from those emerging from non-treated larvae. In contrast, topical or oral administration of captopril to newly emerged adults caused a reduction in oviposition. By evaluating the effect of captopril on ecdysteroid titers and trypsin activity, we revealed an additional physiological role for ACE. Captopril exerted an inhibitory effect on ecdysteroid levels in female but not in male adults. Larvae fed a diet containing captopril exhibited increased trypsin activity. A similar captopril-induced increase in trypsin activity was observed in female adults. In male adults, however, captopril elicited reduced levels of trypsin activity. Our results suggest that captopril downregulates oviposition by two independent pathways, one through ecdysteroid biosynthesis regulation, and the other through regulation of trypsin activity. Apparently, fecundity is influenced by a complex interaction of ACE, trypsin activity, and ecdysteroid levels.

Driving is a very complex task, requiring the cooperation of several different cognitive and psychomotor functions at once. Experimental studies have shown that drugs can have a detrimental influence on capacities that are essential for driving. Cannabis, for example, can acutely reduce some cognitive and psychomotor skills, and these effects are mostly dose dependent. Some deleterious effects of cannabis appear to be additive or even synergistic with those of alcohol, and the combination of both substances results in a prolongation as well as enhancement of their effects. Epidemiological studies have shown that drugs are prevalent in 1–12% of the general driving population, in 6–50% of drivers who are injured or killed in traffic crashes, and in 55–99% of drivers who are suspected of driving under the influence of drugs. The most prevalent drug in most of these studies is cannabis. Drivers who are under the influence of drugs have a higher risk of being involved in or being responsible for a crash. Responsibility analyses show that driving under the influence of cannabis increases the risk of being responsible for an accident, and that this risk increases with increasing cannabis concentration in the blood, indicating a causal relationship between cannabis and crashes. Two major types of driving‐under‐the‐influence of drugs (DUID) legislation exist: “impairment” legislation and “ per se ” legislation. In impairment legislation, the prosecution must demonstrate that the driver was impaired, not fit to drive, or “under the influence”. A “ per se ” law prohibits driving if drugs are present in blood, serum, plasma, or oral fluid above a certain threshold concentration. Since the prosecution does not have to prove that the driver was impaired, this kind of legislation facilitates enforcement. In recent years, the interest in the use of oral fluid as biological matrix for roadside drug screening has increased significantly, as this matrix displays some particularly interesting properties. However the currently available on‐site oral fluid drug testing devices are not reliable enough to be recommended for roadside screening for drivers. Recent methods developed for confirmation analysis, either on blood or on oral fluid, use liquid chromatography (tandem) mass spectrometry (LC‐MS(MS)).