Does Phenazopyridine cause any false positive drug tests?

Yes, phenazopyridine can cause false positive results in certain drug tests, particularly for substances such as methamphetamine and other amphetamines. This over-the-counter medication is used to relieve urinary tract pain and can interfere with the immunoassay tests commonly used in drug screening. If a false positive occurs, confirmatory testing, such as gas chromatography-mass spectrometry (GC-MS), is usually recommended to clarify the results.