Interpretation of Oral Fluid Tests for Drugs of Abuse

Abstract

Oral fluid testing for drugs of abuse offers significant advantages over urine as a test matrix. Collection can be performed under direct observation with reduced risk of adulteration and substitution. Drugs generally appear in oral fluid by passive diffusion from blood, but also may be deposited in the oral cavity during oral, smoked, and intranasal administration. Drug metabolites also can be detected in oral fluid. Unlike urine testing, there may be a close correspondence between drug and metabolite concentrations in oral fluid and in blood. Interpretation of oral fluid results for drugs of abuse should be an iterative process whereby one considers the test results in the context of program requirements and a broad scientific knowledge of the many factors involved in determining test outcome. This review delineates many of the chemical and metabolic processes involved in the disposition of drugs and metabolites in oral fluid that are important to the appropriate interpretation of oral fluid tests. Chemical, metabolic, kinetic, and analytic parameters are summarized for selected drugs of abuse, and general guidelines are offered for understanding the significance of oral fluid tests.

Drug Addiction or False Conviction?

“…However, these methods are generally more complex and time consuming, and it may be difficult to obtain desired turnaround times, especially when this testing is performed by another laboratory. Use of oral fluid as a test matrix is also a promising alternative for monitoring recent medication compliance in pain management (10 ). Oral fluid collection can be performed under direct observation with reduced risk of sample adulteration.…”

“…Unlike urine testing, there can be a close correspondence between drug and metabolite concentrations in oral fluid and in blood. However, the unique characteristics of oral fluid must be taken into account when interpreting these results (10 ).…”

The New Substance Abuse and Mental Health Services Administration Oral Fluid Cutoffs for Cocaine and Heroin-Related Analytes Applied to an Addiction Medicine Setting: Important, Unanticipated Findings with LC-MS/MS

“…Many individuals have a negative view of cocaine (COC) abuse detection by use of OF because post-use detection times have been reported to be as short as 12 and 24 h for COC and benzoylecgonine (BZE), respectively (4 ), vs several days with urine. Several reviews (1)(2)(3) and other documents (5,6 ) compile the numerous studies that have investigated cocaine, heroin, and their metabolites in OF. Much of the OF literature consists of excellent, controlled-administration drug disposition studies (7)(8)(9)(10)(11).…”

“…Impediments to OF acceptance include uncertainty about limits of detection (LODs) and limits of quantification (LOQs) required in OF, the potential need to meet much lower OF analyte detection limits than required with urine samples, and uncertainty about which analytes to target in OF (1)(2)(3). Many individuals have a negative view of cocaine (COC) abuse detection by use of OF because post-use detection times have been reported to be as short as 12 and 24 h for COC and benzoylecgonine (BZE), respectively (4 ), vs several days with urine.…”

“…Interest in oral fluid (OF) 2 as a specimen type for drug testing continues to grow because OF is less subject to sample adulteration, substitution, and dilution than urine and requires a less-invasive sample collection (1)(2)(3). Impediments to OF acceptance include uncertainty about limits of detection (LODs) and limits of quantification (LOQs) required in OF, the potential need to meet much lower OF analyte detection limits than required with urine samples, and uncertainty about which analytes to target in OF (1)(2)(3).…”