Choosing the Right Benzodiazepine Assay: Impact on Clinical Decision Making

Autor: Alan H.B. Wu, Deborah L. French, Judy A. Stone, Judy S. Chang
Rok vydání: 2010
Předmět:
Zdroj: Laboratory Medicine. 41:196-200
ISSN: 1943-7730
0007-5027
Popis: Patient: A 51-year-old, non-ambulatory, homeless African-American woman was admitted to a long-term care facility in September 2008 and used the San Francisco General Hospital Emergency Department as her primary care facility. She was a known intravenous drug abuser and was currently on several prescribed medications including Vicodin (hydrocodone and acetaminophen), Catapres (clonidine), and methadone. Her stay at the long-term care facility was dependent upon her refraining from additional drug abuse. ### Chief Complaint: None. ### History of Present Illness: The patient admitted taking a non-prescribed clonazepam tablet obtained from outside the care facility, prompting her clinician to order a urine drug of abuse screen (DAU) using a commercial CEDIA HS Benzodiazepine immunoassay. It reported positive for benzodiazepines. The clinician proceeded to order DAUs on this patient almost daily to determine reuse of non-prescribed drugs. ### Principal Laboratory Findings: This patient came to the laboratory’s attention when the clinician called approximately 2 weeks after the first positive DAU. The DAU had been positive for a prolonged period and then negative in 1 sample. However, in the next sample, it was positive again. The clinician wanted to know if this positive sample indicated reuse of non-prescribed benzodiazepines by this patient. The clinical laboratory first normalized the semi-quantitative benzodiazepine results to urine creatinine in order to help determine if this was reuse. Seven-aminoclonazepam spiking studies were undertaken using the CEDIA HS immunoassay to try and replicate the high semi-quantitative values seen with this patient. Additionally, the laboratory compared the results from a targeted liquid chromatography tandem mass spectrometry method (LC-MS/MS) to 5 other benzodiazepine assays carried out on the same 9 urine samples from this patient (Table 2, Table 3, and Table 4) in order to further investigate the clinician’s question. 1. If the semi-quantitative urine benzodiazepine results are normalized to urine creatinine, can reuse of non-prescribed benzodiazepines be ruled out? 2. What is the degree …
Databáze: OpenAIRE