Cut-off Concentrations for Drugs of Abuse in Saliva for Dui, Dwi or Other Driving-related Crimes

Investigation of the involvement of drugs in impaired driving would be facilitated by a roadside test for drugs in saliva such as currently exists for alcohol in breath. In the development of a hand-held on-site test for drugs in saliva, targets had to be set for appropriate cut-off values. This was done by consideration of the predominate drug appearing in saliva, the saliva/plasma ratio for that drug and the blood concentrations of the drug likely to cause impairment in driving. This paper describes the results for opiates, marijuana, amphetamines, benzodiazepines and cocaine. The theoretical target value is compared to the RapiScan Saliva Drug Test empirical cut-off values.