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Test ID: BENZU    
Benzodiazepine Confirmation, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Detecting drug use involving benzodiazepines such as alprazolam, flunitrazepam, chlordiazepoxide, diazepam, flurazepam, lorazepam, and triazolam

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Benzodiazepines are any of a group of compounds having a common molecular structure and acting similarly as depressants of the central nervous system. As a class of drugs, benzodiazepines are among the most commonly prescribed drugs in the western hemisphere because of their efficacy, safety, low addiction potential, minimal side effects, and high public demand for sedative and anxiolytic agents.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Positives are reported with a quantitative GC-MS result.

 

Cutoff concentrations:

IMMUNOASSAY SCREEN

<200 ng/mL

 

NORDIAZEPAM BY GC-MS

<100 ng/mL

 

OXAZEPAM BY GC-MS

<100 ng/mL

 

LORAZEPAM BY GC-MS

<100 ng/mL

 

TEMAZEPAM BY GC-MS

<100 ng/mL

 

OH-ETHYL-FLURAZEPAM BY GC-MS

<100 ng/mL

 

7-NH-CLONAZEPAM BY GC-MS

<100 ng/mL

 

ALPHA OH-ALPRAZOLAM BY GC-MS

<100 ng/mL

 

7-NH-FLUNITRAZEPAM BY GC-MS

<50 ng/mL

 

ALPHA OH-TRIAZOLAM BY GC-MS

<100 ng/mL

Interpretation Provides information to assist in interpretation of the test results

Benzodiazepines are extensively metabolized, and the parent compounds are not detected in urine. This test screens for (and confirms) the presence of:

-Nordiazepam, oxazepam (metabolites of chlordiazepoxide)

-Nordiazepam, oxazepam and temazepam (metabolites of diazepam)

-Lorazepam

-Hydroxyethylfluorazepam (metabolite of flurazepam)

-Alpha hydroxyalprazolam  (metabolite of alprazolam)

-Alpha hydroxytriazolam (metabolite of triazolam)

-7-aminoclonazepam (metabolite of clonazepam)

-7-aminoflunitrazepam (metabolite of flunitrazepam)

 

The clearance half-life of long-acting benzodiazepines is >24 hours. It takes 5 to 7 half-lives to clear 98% of a drug dose. Therefore, the presence of a long-acting benzodiazepine greater than the limit of quantification indicates exposure within a 5-day to 20-day interval preceding specimen collection. Following a dose of diazepam, the drug and its metabolites appear in the urine within 30 minutes. Peak urine output is reached between 1 and 8 hours. See Mayo Medical Laboratories Drugs of Abuse Testing Guide at http://www.mayomedicallaboratories.com/articles/drug-book/print-on-demand-select.php for additional information including metabolism, clearance (half-life), and approximate detection times.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements.

 

For chain-of-custody information, see COCH/9426 Chain-of-Custody Processing.

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

1. Disposition of Toxic Drugs and Chemicals in Man. Eighth edition. Edited by RC Baselt. Foster City, CA: Biomedical Publications, 2008

2. Porter W. Clinical toxicology. In Tietz Textbook of Clinical Chemistry. Edited by CA Burtis, DE Bruns. Fourth edition. St. Louis, MO. Elsevier Saunders, 2006, pp 1287-1369

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test