What tests positive for buprenorphine (Subutex)?

From the Guidelines

Buprenorphine is detected by specific drug tests, including enzyme-linked immunosorbent assays (ELISA), enzyme multiplied immunoassay technique (EMIT), or radioimmunoassay (RIA) tests, as well as more sophisticated methods like liquid chromatography-mass spectrometry (LC-MS) or gas chromatography-mass spectrometry (GC-MS). Standard urine drug screens that test for opioids often do not detect buprenorphine because it is a synthetic partial opioid agonist with a different chemical structure than traditional opioids like morphine or heroin 1.

Key Points to Consider

• Buprenorphine can be detected in urine for approximately 1-7 days after use, depending on factors such as dosage, frequency of use, metabolism, and hydration status.
• Blood, saliva, and hair tests can also detect buprenorphine, with detection windows ranging from 24 hours in blood to several months in hair samples.
• The high affinity of buprenorphine for the μ-opioid receptor diminishes the ability of other more potent full agonist opioids to dislodge it from the receptor, which is a beneficial property in the treatment of opioid use disorder 1.

Detection Methods

• Specialized immunoassay tests are required to detect buprenorphine and its primary metabolite, norbuprenorphine.
• LC-MS or GC-MS are used for confirmation of buprenorphine detection.
• The choice of detection method depends on the specific clinical scenario and the need for rapid results versus more accurate confirmation.

Clinical Implications

• Clinicians should be aware of the limitations of standard urine drug screens in detecting buprenorphine and use specialized tests when necessary.
• The detection of buprenorphine in biological samples can be used to monitor adherence to medication-assisted treatment for opioid use disorder.
• The use of buprenorphine for chronic pain management may require careful consideration of the potential for opioid receptor occupancy and the need for additional pain management strategies 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Tests that can Detect Buprenorphine

• Urine tests: Urine is superior to oral fluid for detecting buprenorphine compliance in patients undergoing treatment for opioid addiction 2
• Oral fluid tests: Although less effective than urine tests, oral fluid can be used to detect buprenorphine, but with a higher risk of false negatives 2
• Saliva tests: A point-of-care analyzer using surface-enhanced Raman spectroscopy (SERS) can rapidly measure buprenorphine in patient saliva 3
• Immunoassay tests: Various immunoassay tests, such as cloned enzyme donor immunoassay (CEDIA), enzyme immunoassay (EIA), and homogenous EIA (HEIA), can detect buprenorphine in urine, but may have varying degrees of sensitivity and specificity 4, 5, 6

Factors Affecting Test Results

• Adulteration: Urine and oral fluid specimens can be adulterated or substituted, affecting test results 2
• Metabolites: The presence of buprenorphine metabolites, such as norbuprenorphine, can impact test results 2, 5
• Cutoff values: The choice of cutoff value can influence the sensitivity and specificity of immunoassay tests 5, 6
• Interference: Other substances, such as acetaminophen, caffeine, and nicotine, may not interfere with buprenorphine measurements, but other opioids or drugs may affect test results 3, 6

Test Performance

• Sensitivity and specificity: The sensitivity and specificity of buprenorphine tests can vary depending on the test method and matrix used, ranging from 84% to 100% 4, 5, 6
• Comparison to definitive methods: Immunoassay tests may have similar or lower sensitivity and specificity compared to definitive methods, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS) 6