What if you have a false positive on a drug test?

On Behalf of | Oct 25, 2022 | Criminal Defense

Many workplaces require drug testing of employees. Sometimes there may be a genuine suspicion that you are using drugs, but other times, the tests happen randomly. You may also have to undergo drug testing as a student.

Here are some things you need to know in the event of a positive drug test that you believe to be false.

How common are false positives?

The chances that you will receive a false positive on a drug test are small but not insignificant. According to Drugs.com, false positives represent approximately 5% to 10% of all drug tests administered.

Can things that you have eaten or taken result in false positives?

Common medications that you may take, and sometimes food that you may eat, may result in false positives for certain drugs:

  • Lidocaine, a topical anesthetic, can produce a false positive for cocaine
  • Sertraline, an antidepressant, can produce a false positive for benzodiazepines
  • Efavirenz, an antiviral medication used to treat HIV, can produce a false positive for cannabinoids
  • Dextromethorphan, a cough medication, can produce a false positive for opioid narcotics and PCP, a hallucinogen
  • Poppy seeds, used as a flavoring for baked goods, can produce a false positive for opioids.

Some of these medications, including dextromethorphan and lidocaine, are available to you without a prescription. Anyone can buy and consume poppy seeds despite the fact that they contain small amounts of codeine and morphine.

What do you do if you receive a false positive on a drug test?

If you receive a false positive result, request confirmatory testing, such as a Gas Chromatography Mass Spectrometry test. This is the “gold standard” of drug testing and can differentiate between the metabolites of illicit drugs and those of legitimate medications.