Enter a medication or substance to see which urine immunoassay panels it may interfere with — including platform-specific caveats and false negative gaps.
Try a generic name, brand name, or drug class. Searches generic names, brand names, and common aliases.
Start typing a drug name above to check for immunoassay interference.
Results draw from TP-UDT-FP-V02, ToxiPharm's clinical UDT cross-reactivity reference.
This tool identifies the most commonly documented cross-reactants for urine drug test immunoassays and does not represent an all-inclusive list. Cross-reactivity varies by immunoassay platform, antibody lot, analyte concentration, and specimen matrix. A negative search result does not confirm the absence of cross-reactivity for a given substance. Clinically unexpected positive or negative results should be confirmed by LC-MS/MS. This tool is intended for use by qualified clinicians, medical review officers, and drug program administrators as a reference aid only. It does not constitute medical, legal, or regulatory advice.
Source: TP-UDT-FP-V02 — ToxiPharm LLC (2026). William Bundy Jr., PharmD. Data derived from published peer-reviewed literature and manufacturer immunoassay cross-reactivity guides.