Experimental studies of cannabis and other drugs indicate that, to interpret individual cases correctly, it is not only important to know whether a narcotic has been consumed. It is also essential to have objective data, such as the dose administered and the interval between consumption and participation in road traffic. Such data can be obtained only by quantifying the active substance and perhaps also its metabolites. This paper describes methods for the quantitative estimation of cannabinoids and opiates in urine and blood samples, for the determination of driving performance.E xamples are given of specific chemical criteria, whose satisfaction shows that a person is unfit to drive. When analysing blood or serum, reference must be made to internal standards for quantification purposes.
Abstract