Oral Fluid Drug Testing in Pain Management Practice: Factors to Consider Before Choosing the Alternative Biological...

As the use of pharmacological agents, particularly opioid analgesics, has increased in the past 2 decades, so have the substance abuse risks, along with the prevalence of overdose deaths, addiction, and illicit drug use. Accordingly, close monitoring of patients to ensure medication compliance and to identify improper drug use becomes a critical task for pain-management practitioners.

Oral fluid is an emerging biological matrix for clinical drug testing. It offers noninvasive, less hazardous, and directly observable sample collection with minimal potential for adulteration. Oral fluid can be collected multiple times in a short period and shows a stronger correlation with blood than urine concentrations. Usability of oral fluid testing had been limited by the sensitivity of analytical methods. The volume of oral fluid samples is typically much smaller than that of urine samples. Furthermore, oral fluid drug concentrations can be 10- to 100-fold lower than urine concentrations depending on analytes. Recent advances in analytical technologies lead to the growing popularity of oral fluid testing and subsequent need for scientific data to aid in interpretation of oral fluid test results.

This review presents preanalytical, analytical, and postanalytical considerations associated with oral fluid drug testing for those contemplating the implementation of this alternative biological matrix in pain-management practice. Comparison with urine testing, collection procedure, drug stability, available technologies, scope of analysis, and drug disposition are discussed. As with other monitoring tools, oral fluid testing has advantages and limitations. The most important consideration is staying informed to use the testing within its capability.