Oral Fluid

Most drugs used by persons are present in oral fluid and the collection of this fluid can be achieved with little invasion of a person's privacy. Hence, this specimen has received wide application in situations requiring rapid drug screening. Such applications include workplace drug testing, particularly in safety critical industries (aviation, train and truck driving, mining and petrochemical industries). Oral fluid concentrations of a number of illicit drugs tend to be higher than their corresponding blood concentrations (e.g., Î"⁹-tetrahydrocannabinol, morphine and other opiates, amphetamines, and cocaine). While there is some correlation of oral fluid with blood concentrations of drugs, in practice, it is not possible to calculate with any precision a circulating blood concentration from a concentration in oral fluid. This is compounded by the various mechanisms of incorporation of drugs into oral fluid and the many factors that affect oral fluid production and drug concentration. Drugs in oral fluid can be detected by point-of-care testing devices or in the laboratory by immunoassay methods; however, confirmation must occur in the laboratory by appropriate mass spectral methods.