Will a urine benzodiazepine screen be positive in a patient who is only taking Kadian (extended‑release morphine) and methadone?

No, benzodiazepine screens will be negative in patients taking only Kadian (morphine) and methadone

A patient taking only Kadian (extended-release morphine) and methadone should not test positive for benzodiazepines on urine drug screening, as these are opioid medications that do not cross-react with benzodiazepine immunoassays.

Why Opioids Don't Trigger Benzodiazepine Screens

Benzodiazepine immunoassays are designed to detect benzodiazepines and their metabolites (typically oxazepam as the common metabolite) 1. These tests are class-specific and do not cross-react with opioid medications like morphine (Kadian) or methadone 2, 3.

• Morphine (the active ingredient in Kadian) will only trigger opioid/opiate immunoassays 4, 3
• Methadone requires its own specific immunoassay and will not be detected on standard opiate screens 2, 3
• Neither medication has chemical structures that would cause cross-reactivity with benzodiazepine tests

Important Caveats About Benzodiazepine Testing

False-Positive Triggers (Not from Opioids)

While opioids won't cause false-positive benzodiazepine results, other medications can 5:

• Sertraline
• Oxaprozin (NSAID)
• Certain antihistamines

False-Negative Benzodiazepine Results

Standard benzodiazepine immunoassays may miss certain benzodiazepines even when they are present 1, 2:

• Clonazepam is not metabolized through the oxazepam pathway and is commonly missed 1
• Alprazolam may not be detected by some immunoassays 2
• Designer benzodiazepines (flualprazolam, flubromazolam, etizolam) are frequently undetected by standard panels 6

Clinical Interpretation

If a patient on only Kadian and methadone shows a positive benzodiazepine screen:

1. Suspect undisclosed benzodiazepine use (prescribed or illicit)
2. Review all medications for potential cross-reactants 5
3. Confirm with GC-MS or LC-MS-MS to identify the specific substance 1, 2
4. Consider designer benzodiazepines if confirmatory testing is negative for standard benzodiazepines 6

If the screen is negative for benzodiazepines in this patient, this is the expected result and confirms no benzodiazepine exposure (within the limitations of the test's detection window and sensitivity to specific benzodiazepines).

What You Should Expect on UDS

A patient taking only Kadian and methadone should show:

• Positive for opiates/morphine (from Kadian) 3
• Positive for methadone (if methadone-specific immunoassay is ordered) 2
• Negative for benzodiazepines (unless taking benzodiazepines separately)