title: Cross-reactivity of acetylfentanyl and risperidone with a fentanyl immunoassay.
abstract: Fentanyl and its analogs, such as acetylfentanyl, have become a concern for potential abuse. Fentanyl compliance monitoring and urine drug testing are becoming increasingly necessary; however, a limited number of fentanyl immunoassays have been validated for clinical use. The purpose of this study was to validate the use of the DRI® fentanyl immunoassay, determine the potential cross-reactivity of acetylfentanyl and other pharmaceuticals, and investigate acetylfentanyl use in San Francisco. All urine toxicology samples from patients presenting to the emergency department were analyzed using the fentanyl immunoassay for 4 months. Positive samples were analyzed qualitatively using liquid chromatography-high resolution mass spectrometry (LC-HRMS) for fentanyl, fentanyl metabolites, fentanyl analogs and greater than 200 common drugs and metabolites. Subsequently, quantitative analysis was performed using LC-tandem mass spectrometry (LC-MS-MS). Acetylfentanyl, risperidone and 9-hydroxyrisperidone were found to cross-react with the fentanyl immunoassay. No acetylfentanyl was detected in our emergency department patient population. The fentanyl immunoassay demonstrated 100% diagnostic sensitivity in a subset of urines tested; however, the specificity was only 86% due to seven false-positive samples observed. Five of the seven samples were positive for risperidone and 9-hydroxyrisperidone. The DRI® fentanyl immunoassay can be used to screen for fentanyl or acetylfentanyl; however, confirmatory testing should be performed for all samples that screen positive.
authors.affiliation: Department of Laboratory Medicine, University of California, San Francisco General Hospital, 1001 Potrero Ave. NH2M16, San Francisco, CA 94110, USA.
authors.forename: Bei-Tzu
authors.initials: BT
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, University of California, San Francisco General Hospital, 1001 Potrero Ave. NH2M16, San Francisco, CA 94110, USA.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Colby
authors.affiliation: Department of Laboratory Medicine, University of California, San Francisco General Hospital, 1001 Potrero Ave. NH2M16, San Francisco, CA 94110, USA.
authors.forename: Alan H B
authors.initials: AH
authors.lastname: Wu
authors.affiliation: Department of Laboratory Medicine, University of California, San Francisco General Hospital, 1001 Potrero Ave. NH2M16, San Francisco, CA 94110, USA kara.lynch@ucsf.edu.
authors.forename: Kara L
authors.initials: KL
authors.lastname: Lynch
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D003429:Cross Reactions; D005189:False Positive Reactions; D005283:Fentanyl / Q000652:urine*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007555:Isoxazoles / Q000652:urine; D000068882:Paliperidone Palmitate; D011743:Pyrimidines / Q000652:urine; D015203:Reproducibility of Results; D018967:Risperidone / Q000652:urine*; D012495:San Francisco; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000175:diagnosis; D053719:Tandem Mass Spectrometry
chemical_list: D007555:Isoxazoles; D011743:Pyrimidines; D018967:Risperidone; D000068882:Paliperidone Palmitate; D005283:Fentanyl