Oxycodone Does Not Cause False-Positive Bupropion Results
Oxycodone does not cause false-positive results for bupropion on urine drug screens. This question appears to reflect a misunderstanding of drug testing—the concern is typically whether bupropion causes false-positives for other substances (like amphetamines), not whether other drugs test positive for bupropion.
Understanding the Actual Clinical Issue
The relevant clinical scenario involves bupropion causing false-positive results for amphetamines, not the reverse:
- Bupropion metabolites can cause false-positive amphetamine results on certain enzyme-linked immunoassay screening tests when concentrations exceed 500 ng/mL 1
- Therapeutic use of bupropion was the most frequent cause of false-positive amphetamine screens in one emergency department study, accounting for 41% of unconfirmed positive amphetamine results 2
- Two specific immunoassay kits (Amphetamine ULTRA and Syva EMIT II) are particularly susceptible to cross-reactivity with bupropion metabolites 1, 2
Why Oxycodone Would Not Test Positive for Bupropion
- Oxycodone is a mu-, delta-, and kappa-opioid receptor agonist with a completely different chemical structure than bupropion, which is a norepinephrine-dopamine reuptake inhibitor 3, 4
- Drug screens test for the presence of specific drug classes or their metabolites—oxycodone would only trigger positive results on opioid panels, not on tests designed to detect antidepressants 5
- Standard immunoassays may not even detect oxycodone reliably, as it is a semisynthetic opioid that often requires specific testing beyond routine opiate screens 5
Critical Clinical Pitfall to Avoid
- Never assume immunoassay screening results are definitive—they are presumptive only and require confirmatory testing with gas chromatography-mass spectrometry (GC-MS) when results are unexpected or will impact patient management 5, 6
- Always obtain a complete medication history including all prescription medications, over-the-counter drugs, and supplements before interpreting any positive drug test 5, 7
- Request confirmatory GC-MS testing when results are unexpected, as this method can definitively identify specific drug molecules and differentiate them from structurally similar compounds 5
If You Encounter an Unexpected Positive Result
- Document the complete medication list on the laboratory request form 5
- Discuss unexpected results with your local laboratory or toxicologist before making clinical decisions 5, 7
- Never make consequential clinical decisions (such as discharging patients from care or legal actions) based solely on immunoassay results without confirmation 5