Fentanyl Screen with Reflex, Random, Urine

Casandra

Casandra Test Code MC78669Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID FENRCPT Code 80307

Fentanyl Screen with Reflex, Random, Urine

Clinical Use

Use

Screening for drug abuse or use involving fentanyl and confirmation of fentanyl if present in the screen. The initial immunoassay provides a presumptive screen with high true-negative rate but potential for false positives due to cross-reactivity; a positive screen triggers confirmation by liquid chromatography tandem mass spectrometry (LC‑MS/MS) with quantification. Negative results indicate no fentanyl above ~0.20 ng/mL detected (screen cutoff: 2 ng/mL), while presence of fentanyl above 0.20 ng/mL or norfentanyl above 1.0 ng/mL indicates strong evidence of fentanyl use.

Special Instructions

Reflex testing is performed when the initial screen is positive, using LC‑MS/MS confirmation at additional charge. For chain‑of‑custody purposes, a separate kit (T282) and test (FENTX) must be ordered. If adulteration or creatinine assessment is needed, additional urine adulterants survey testing should be ordered. Use Therapeutics Test Request (T831) form if not ordering electronically.

Limitations

As an immunoassay-based screen, results may yield false positives due to antibody cross-reactivity and false negatives depending on antibody specificity. Biologic factors such as fluid intake can affect urine drug concentration and test sensitivity. Confirmation by LC‑MS/MS is required for positive screens to confirm fentanyl or metabolite presence.

Test Details

New York Approved