Bupropion Can Cause False Positive Results for Amphetamines but Not Specifically for MDMA
Bupropion does not typically cause false positive results specifically for MDMA (ecstasy), but it is a common cause of false positive results for amphetamines on immunoassay screening tests. 1
Mechanism and Evidence
Bupropion has been well-documented to interfere with immunoassay drug screens:
- In a comprehensive study of 10,011 urine drug screens, bupropion was found to be the most frequent cause of false positive amphetamine results, accounting for 41% of all false positive amphetamine screens 1
- While bupropion can trigger false positives for amphetamines in general, the evidence does not specifically indicate that it causes false positives for MDMA in particular
- One study did identify bupropion as potentially causing false positives for both amphetamines and LSD using CEDIA immunoassays, but did not specifically mention MDMA 2
Confirmation Testing
When a positive screening result occurs:
- Confirmatory testing using gas chromatography/mass spectrometry (GC-MS) or liquid chromatography/mass spectrometry (LC-MS/MS) is essential to distinguish between true and false positive results 3
- These confirmatory methods are considered the gold standard and can reliably differentiate between bupropion and actual drugs of abuse 1
- All positive screening results should be confirmed before making any significant clinical or legal decisions 3
Other Medications That Can Cause False Positives
Several medications can cause false positive results on drug screening tests:
- For amphetamines: antidepressants (bupropion, sertraline, trazodone, venlafaxine), antihistamines (brompheniramine, diphenhydramine, doxylamine), antipsychotics (chlorpromazine, quetiapine, thioridazine), and over-the-counter medications (dextromethorphan, nasal inhalers) 4, 5
- For MDMA specifically: fenofibrate has been documented to cause false positive results on both CEDIA and DRI immunoassays for MDMA 6
Clinical Implications
When interpreting drug test results:
- Always document any medications the patient is currently taking to help interpret results 3
- Consider the timing of medication use relative to testing, as detection windows vary by substance 3
- Unexpected positive results should prompt a conversation with the patient rather than immediate punitive action 3
- False positive results are common enough that immunoassay results should always be considered presumptive until confirmed by more specific methods 5
Key Pitfalls to Avoid
Don't make decisions based solely on immunoassay results - confirmatory testing is essential, especially when clinical history doesn't match screening results 3
Don't overlook medication history - always consider current medications when interpreting drug test results 3
Don't assume cross-reactivity patterns are the same across different immunoassay brands - different test manufacturers may have different cross-reactivity profiles 5
Don't confuse general amphetamine false positives with specific MDMA false positives - while bupropion commonly causes false positives for amphetamines, evidence for specific MDMA false positives from bupropion is limited 1, 5