Forensic science international
-
A zero-concentration limit for controlled scheduled drugs in the blood of motorists was introduced in Sweden in 1999 and the annual number of arrests for driving under the influence of drugs (DUID) has since increased eight-fold. However, for prescription drugs that might cause impairment (e.g. benzodiazepines) additional proof is needed to justify prosecution, such as whether the medication was being misused. Over a 2-year period, we found 94 cases of DUID in which the concentrations of diazepam in blood was 1.1 microg/g or more. ⋯ Other psychoactive prescription drugs were identified in blood including alprazolam, flunitrazepam, oxazepam, zolpidem and zopiclone. This case series of DUID suspects demonstrate the high frequency of polydrug use showing preference for illicit drugs like amphetamine, cannabis and heroin, in that order. Furthermore, Swedish traffic delinquents frequently overdose with prescription drugs as exemplified here by unusually high concentrations of D and its active metabolite ND.