For Prescribers

Performing Urine Drug Tests

Urine drug testing is an important component of opioid prescribing.

About Urine Drug Tests:

  • Initial tests are generally done with immunoassays.
  • Risk include:
    • False negatives due to cut-offs for test sensitivity
    • False positive due to cross reactivity with other drugs.
    • Follow-up unexpected findings: Send for further analysis using gas chromatography/mass spectroscopy to identify specific compounds.
  • Be aware of opioid metabolic pathways to fully analyze test results (see figure below).
  • Opioid Metabolism Pathway

Important: Urine drug testing: Must be integrated and synthesized the patient’s entire history and clinical picture.

  • Etiology of a particular test result cannot determined. (i.e. If the urine test is negative for opioids, unknown if patient diverting medication vs. using more rapidly than directed).
  • Dedicated deceivers can beat the system.

See also:


  1. Christo PJ et al. Urine drug testing in chronic pain. Pain Physician 2011;14:123-143.
  2. Heit HA and Gourlay DL. Urine drug testing in pain medicine. J Pain Symptom Manage 2004;27:260-267.
  3. Peppin JF et al. Recommendations for urine drug monitoring as a component of opioid therapy in the treatment of chronic pain. Pain Medicine 2012;13:886-896.
  4. Reisfield GM et al. ‘False-positive’ and ‘false-negative’ test results in clinical urine drug testing. Bioanalysis 2009;1(5):937-952.