Drug testing in the clinical setting can provide information that improves patient care. The results of drug testing can often prompt important clinical discussions with patients. For example, absence of an expected drug could suggest poor adherence or diversion, whereas detection of a non-prescribed licit or illicit drug could raise concerns regarding substance misuse. Discrepancies between expected and actual results could also call attention to patient intolerance to medication side effect or potential medical factors affecting drug disposition.
Various sample types can be used for drug testing. Urine is the most widely used and well-established sample type at present and offers the broadest options for drug testing. However, urine-based drug testing has several potential drawbacks including inconvenience and patient embarrassment, sample integrity problems when collection is not observed, and lack of privacy when specimen collection must be observed.
The decision to use oral fluid drug testing should take into account the potential benefits and drawbacks of this matrix as they apply to individual clinical scenarios. The main advantage of oral fluid testing is the ease of observing sample collection, while the disadvantages relate to shorter drug detection windows, lower drug concentrations in the sample, and limited specimen volume.