Do Medications Result in False Positives?

Certain medications can result in false positives on drug tests. A false positive occurs when a drug test detects the presence of a substance that is chemically similar to an illicit drug, even though the individual has not used the illicit drug. Here are some common examples of medications and the substances they might be mistaken for:

Over-the-counter medications

• Pseudoephedrine (found in cold medications) can be mistaken for amphetamines.
• Ibuprofen (used for pain relief) has been known to cause false positives for THC, the active ingredient in marijuana.

Prescription medications

• Antibiotics such as amoxicillin can sometimes cause false positives for cocaine.
• Antidepressants like sertraline (Zoloft) can result in false positives for benzodiazepines or LSD.
• ADHD medications like methylphenidate (Ritalin) can be mistaken for amphetamines.

Other substances

• Certain antiretroviral drugs used to treat HIV can cause false positives for marijuana.
• Quinolone antibiotics can sometimes be mistaken for opiates.

When a drug test yields a non-negative result, it may be reviewed by a Medical Review Officer (MRO). An MRO is a licensed physician responsible for interpreting and evaluating test results, considering any legitimate medical explanations for a positive result. The MRO will review the individual's medical history, prescription medications, and other relevant information.

Proper drug and alcohol testing training is crucial for technicians to interpret test results and identify potential false positives correctly. While technicians can perform initial screenings, only Medical Review Officers (MROs) have the authority to determine if a result is a false positive or a legitimate non-negative.

An MRO is a licensed physician responsible for interpreting and evaluating test results in the context of an individual’s medical history, prescription medications, and other relevant factors are needed to ensure that any positive test result due to legitimate medications or other substances is accurately identified and that individuals are not unfairly penalized. Confirmatory testing, such as gas chromatography-mass spectrometry (GC-MS), is also used to verify initial test results and eliminate the possibility of false positives.