Can Ibuprofen Cause A False Positive Drug Test?

In our latest question and answer, our pharmacist discusses whether or not ibuprofen can cause a positive drug test.

Dec 14, 2017

Jackie asked

Is there any chance I could test positive for Ultram (tramadol) if I’ve taken 800mg of ibuprofen?

Answer

Ibuprofen isn't typically associated with drugs that are known to cause false positives for opioid medications (such as tramadol). Ibuprofen is however associated with false positives for the following:

  • Barbituates
  • Phencyclidine (PCP)

Even though ibuprofen isn't associated with false positive drug tests in your case, you can't rule it out as a potential factor in your test results. There also may be a different offending agent that you aren't aware of that is causing the problem. 

False positives are relatively common on initial screenings (i.e. common urine tests). In fact, it has been reported that over 20% of drug tests result in a false positive reading.The good news is that if you do test positive for a substance which you know you have not consumed, there are confirmation tests that are far more accurate.

The main issue with common drug tests are their lack of selectivity. Most employers use simple, urine based immunoassay tests such as the EIA (Enzyme Linked Immunoassay) test or the CEDIA (Closed Enzyme Donor Immunoassay) test. These tests work by utilizing antibodies to react to a specified drug compound. When the specified drug is present in a urine sample, an antibody binds to it, producing a reaction and is recorded as a positive test. There is a fairly big problem with cross-reactivity in these tests. Compounds or substances that are not being tested for can sometimes react with the wrong antibody, resulting in a false positive test.

Below, we list common prescription medications and associated drugs that can cause false positives.

Amphetamine

Drugs known to cause false positives:

  • Amantadine
  • Bupropion
  • Labetalol
  • Methylphenidate
  • Phenylephrine
  • Pseudoephedrine
  • Trazodone
  • Venlafaxine

Barbiturates

Drugs known to cause false positives:

  • Ibuprofen
  • Naproxen

Benzodiazepines

    Drugs known to cause false positives:

    • Oxaprozin
    • Sertraline

    Opioids

      Drugs known to cause false positives:

      • Oxaprozin
      • Sertraline
      • Dextromethorphan
      • Diphenhydramine
      • Doxylamine
      • Quinolones
      • Levofloxacin 

      To reiterate, ibuprofen is not well known to cause false positives for opioids like tramadol, but a false positive nonetheless is theoretically possible. If you did test positive and want to clear your name, request a more accurate test such as gas chromatography-mass spectrometry (GC-MS). These tests do not use antibodies and can accurately determine the exact molecule in question.

      Ready for a more personal experience with your meds?