Clinical Toxicology | 2019
An assessment of urine THC immunoassay in healthy volunteers receiving an oral proton-pump inhibitor
Abstract
Abstract Introduction: Limitations of urine drug-screening (UDS) by immunoassay include false-positive results. Pantoprazole, a proton-pump inhibitor (PPI), is reported to cause false-positive results for THC on UDS. The objective of this study was to determine if oral PPIs cause false-positive THC results using the THC One Step Marijuana Test Strip®. Methods: Eligible healthy volunteers completed a 5-day course of a PPI followed by urine testing using the THC One Step Marijuana Test Strip®. Phase one included 3 subjects taking pantoprazole 40\u2009mg once daily for 5\u2009days. On day 5, urine specimens underwent THC screening. Phase two included 9 subjects randomized to 5-day supply of once-daily oral esomeprazole 20\u2009mg, lansoprazole 15\u2009mg, or omeprazole 20\u2009mg. All study methods and testing mirrored those in phase one. Results: All 12 subjects completed the study protocol. All urine samples collected on day 5 were negative for THC in all subjects. Discussion: Our results demonstrate that oral PPIs did not cause a false-positive THC using the THC One Step Marijuana Test Strip®. Limitations include small sample size, use of a single commercial immunoassay, and inability to confirm medication compliance. Further, large-scale research using other commercial urine immunoassays is warranted.