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Test ID: BENZU Benzodiazepines Confirmation, Random, Urine

Reporting Name

Benzodiazepines Confirmation, U

Useful For

Monitoring compliance of benzodiazepines such as alprazolam, flunitrazepam, chlordiazepoxide, diazepam, flurazepam, lorazepam, and triazolam

Specimen Type


Advisory Information

1. For situations where chain of custody is required, a Chain-of-Custody Kit (T282) is available. For chain-of-custody testing, order BENZX / Benzodiazepines Confirmation, Chain of Custody, Random, Urine.

2. Additional drug panels and specific requests are available. Call 800-533-1710 or 507-266-5700.

3. If urine creatinine is required or adulteration of the sample is suspected, order ADULT / Adulterants Survey, Random, Urine.

Specimen Required

Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 10 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.

Additional Information:

1. No specimen substitutions.

2. STATS are not accepted for this test.

Specimen Minimum Volume

5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 14 days
  Frozen  14 days
  Ambient  72 hours

Reference Values



Cutoff concentrations:

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

Day(s) and Time(s) Performed

Monday through Friday; Varies

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BENZU Benzodiazepines Confirmation, U 90890-5


Result ID Test Result Name Result LOINC Value
21441 Nordiazepam-by GC/MS 16228-9
20655 Oxazepam-by GC/MS 16201-6
20656 Lorazepam-by GC/MS 17088-6
20657 Temazepam-by GC/MS 20559-1
20658 OH-Ethyl-Flurazepam-by GC/MS 20532-8
20659 7-NH-Clonazepam-by GC/MS 51776-3
20670 Alpha OH-Alprazolam-by GC/MS 16348-5
20660 7-NH-Flunitrazepam-by GC/MS 51777-1
20661 Alpha OH-Triazolam-by GC/MS 49876-6
20663 Benzodiazepines Interpretation 16195-0
20664 Chain of Custody 77202-0

Clinical Information

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.


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)


-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 more than 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 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 Clinic Laboratories Drugs of Abuse Testing Guide for additional information including metabolism, clearance (half-life), and approximate detection times.

Clinical Reference

1. Disposition of Toxic Drugs and Chemicals in Man. 10th edition. Edited by RC Baselt. Biomedical Publications, 2014

2. Langman LJ, Bechtel LK, Meier BM, Holstege C: Chapter 41:Clinical Toxicology. In Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Edited by N Rifai, AR Horvath, CT Wittwer. Sixth edition. Elsevier, 2018, pp 832-887

3. Mihic SJ, Mayfield J, Harris RA: Hypnotics and sedatives. In Goodman and Gilman's The Pharmacological Basis Of Therapeutics. 13th edition. Edited by LL Brunton, R Hilal-Dandan, BC Knollmann. McGraw-Hill Education; 2017

Analytic Time

3 days

Method Name

Gas Chromatography-Mass Spectrometry (GC-MS) Confirmation with Quantitation


If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen. 

Mayo Clinic Laboratories | Therapeutics Catalog Additional Information:

mml-benzodiazepines, mml-substancemonitoring