Question & Answer

Q: I had a false-positive urine screening test result for tetrahydrocannabinol (THC) — the chemical responsible for most of marijuana’s psychological effects. Could taking pantoprazole (PROTONIX) have caused this result?

A: Pantoprazole is a proton pump inhibitor (PPI) — a family of drugs that inhibit the production of stomach acid and are commonly used to treat heartburn and peptic ulcers. The other drugs in this family are dexlansoprazole (DEXILANT), lansoprazole (PREVACID, PREVACID 24HR), omeprazole (PRILOSEC, PRILOSEC OTC, YOSPRALA, ZEGERID, ZEGERID OTC), rabeprazole (ACIPHEX) and esomeprazole (NEXIUM, NEXIUM 24HR, VIMOVO). Some of these drugs are available over the counter. We have designated all of these drugs as Limited Use.

The drug labeling for pantoprazole warns that there have been cases of false-positive test results for THC in patients taking PPIs.[1] A false-positive drug test result occurs when a test incorrectly indicates that a drug is present in a person’s system when it is not present. A similar warning appears on the labeling for dexlansoprazole,[2] lansoprazole,[3] omeprazole[4] and rabeprazole[5]. Esomeprazole does not have this warning on its labeling,[6] but patients should assume that false-positive urine screening test results for THC could occur with use of this drug.

If you take one of the PPIs, do not use THC-containing products and receive a positive urine screening test result for THC, ask your doctor to perform an alternative confirmatory screening method to verify the result.
 

References

[1] Pfizer. Label: pantoprazole (PROTONIX). April 2019. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/020987s055,022020s017lbl.pdf. Accessed September 20, 2019.

[2] Takeda Pharmaceuticals America, Inc. Label: dexlansoprazole (DEXILANT). June 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/022287s029s030lbl.pdf. Accessed September 20, 2019.

[3] Takeda Pharmaceuticals America, Inc. Label: lansoprazole (PREVACID). June 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/020406s087s088,021428s034s035lbl.pdf. Accessed September 20, 2019.

[4] AstraZeneca. Label: omeprazole (PRILOSEC). August 2018. . Accessed September 20, 2019.https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/022056s021lbl.pdf

[5] Eisai Inc. Label: rabeprazole (ACIPHEX). June 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/020973s039lbl.pdf. Accessed September 20, 2019.

[6] AstraZeneca. Label: esomeprazole (NEXIUM). June 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/021153s053,022101s017,021957s020lbl.pdf. Accessed September 20, 2019.