title: Unusual false-positive case of urinary screening for buprenorphine.
abstract: Buprenorphine is a centrally acting analgesic drug that is administered for the management of opioid dependence and as an analgesic drug for the treatment of chronic pain. The growing use of this substance has determined an increased need for laboratory testing for either detection and confirmation of the illicit use or monitoring compliance as a substitution therapy for opioid dependence. We describe here the case of urinary sample adulteration with exogenous buprenorphine (6,952 ng/ml), which has led to afalse-positive immunoassay test result (14.9 ng/ml) on a subsequent sample due to a phenomenon of instrumental carry-over. This unusual case confirms the importance to take into account adulteration when screening urines for buprenorphine in patients undergoing substitution therapy for opioid dependence, routinely perform a confirmation assay on positive samples, and rule out instrumental carry-over.
authors.affiliation: U.O. Diagnostica Ematochimica, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy. glippi@ao.pr.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
authors.forename: Araelsis
authors.initials: A
authors.lastname: Romero
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Cervellin
authors.forename: Mariella
authors.initials: M
authors.lastname: Mercadanti
mesh_terms: D002047:Buprenorphine / Q000031:analogs & derivatives / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D019544:Equipment Failure Analysis; D005189:False Positive Reactions; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards*; D009294:Narcotics / Q000652:urine; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods / Q000592:standards*
chemical_list: D009294:Narcotics; D002047:Buprenorphine; C043585:norbuprenorphine