13 Medications That May Cause a False Positive on Drug Tests

Posted by William Aron | Sep 15, 2022

Drug tests are used to identify the presence of certain substances and medications in the body. Unfortunately, drug test results are not 100% accurate, and false positives may occur. “False positives” are when drug tests flag a medication or substance you do not actually take. Sometimes, these are caused by lab errors, but certain medications have also been known to trigger fictitious positive results.

When drug tests incorrectly mark people positive for drugs they have not taken, they could face severe, unwarranted consequences. If you or someone you care about is facing penalties for erroneous drug test results, an Aron Law Firm Santa Barbara criminal defense lawyer may defend your case by providing irrefutable evidence that a medication you were taking has skewed your drug test results.

Could Your Medication Be the Reason You Failed a Drug Test?

Often, false positives on drug tests are the result of taking medications prescribed by medical doctors. You could fail a drug test for taking medications such as:

  • Antihistamines, such as Benadryl: Diphenhydramine, the active ingredient in these medications, helps treat itching, allergies, and cold symptoms; but it may also trigger a positive result for opioids, opiates, or PCP on a drug test.
  • Bupropion, such as Wellbutrin: Antidepressants that use bupropion as their active ingredient could produce a false positive result for amphetamine or methamphetamine.
  • Certain Decongestants, such as Sudafed: Many decongestants use pseudoephedrine to relieve sinus and nasal congestion, but on a drug test, it could appear as amphetamine or methamphetamine.
  • NSAIDs, such as Motrin, Advil, Aleve, and Naprosyn: Ibuprofen and naproxen are classified as nonsteroidal anti-inflammatory medications (NSAIDs). Often used to help treat inflammation, fever, and pain, taking an OTC NSAID before a urine test could bring up a false positive for barbiturates or THC.
  • OTC Cough Suppressants, such as Robitussin and Delsym: The main ingredient in many cough syrups is dextromethorphan, which could show positive for PCP in a urine test.
  • Oxaprozin, also known as Daypro: Used to treat arthritis pain, oxaprozin may result in a positive result for benzodiazepines.
  • Phentermine, also known as Adipex-P: FDA-approved to lower appetite, taking phentermine may flag for amphetamines in a urine test.
  • PPIs, such as pantoprazole (Protonix): Proton pump inhibitors (PPIs) may alleviate heartburn symptoms and gastroesophageal reflux disease (GERD), but, on a drug test, they may elicit a false positive result for THC.
  • Promethazine: Intended to relieve nausea and vomiting, phenothiazines may produce a false positive result for amphetamine or methamphetamine in a drug test.
  • Quetiapine, such as Seroquel: An atypical antipsychotic used to treat mental health conditions like schizophrenia and bipolar disorder. Taking quetiapine could trigger a positive result for the opioid methadone in a drug test.
  • Quinolone Antibiotics, such as Levofloxacin (Levaquin) and Ofloxacin: Used to treat bacterial infections, they may cause a false positive for opiates, amphetamine, or methamphetamine in a urine test.
  • SNRIs, such as Effexor XR or Pristiq: Serotonin-norepinephrine reuptake inhibitors (SNRIs), such as venlafaxine and desvenlafaxine, are antidepressants that could cause a false positive for PCP.
  • SSRIs, such as Zoloft: Using selective serotonin reuptake inhibitors (SSRIs) may result in a positive result for benzodiazepines or LSD in a urine drug test.

When you are on probation, failing a drug test could lead to severe penalties as it is a violation under California Penal Code 1203.3. If an over-the-counter, prescribed medication, or something else triggered a false positive on your drug test, a criminal defense attorney can create a solid defense strategy for your case.

Defend a False Positive on a Drug Test With a California Criminal Defense Attorney

At Aron Law Firm, we have successfully minimized the penalties associated with false positive drug test results for numerous clients. Whether your medication or another factor played into your false positive result, you need a criminal defense lawyer on your side.

Partner with a California attorney who knows what it takes to defend inaccurate drug test results. Contact Aron Law Firm 24 hours a day, seven days a week, by calling (805) 618-1768 or completing our contact form.