Sign in →

EPIC CODE: LAB5349 Benzodiazepines Confirmation, Random, Urine

Additional Codes

Sunquest:   BENZUM
Mayo:          BNZU

Ordering Guidance

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


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

Additional Testing Requirements

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

Specimen Required

Supplies: Aliquot Tube, 5 mL (T465)

Collection Container/Tube: Plastic urine container

Submission Container/Tube: Plastic, 5-mL tube

Specimen Volume: 1 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative

Additional Information:

1. No specimen substitutions.

2. STAT requests are not accepted for this test.

3. Submitting less than 1 mL will compromise our ability to perform all necessary testing.

Secondary ID


Useful For

Detecting drug use involving benzodiazepines such as alprazolam, chlordiazepoxide, clonazepam, diazepam, midazolam, oxazepam, temazepam, clobazam, flunitrazepam, flurazepam, lorazepam, prazepam, triazolam, and zolpidem

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Benzodiazepines Confirmation, U

Specimen Type


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 7 days
  Frozen  14 days

Reject Due To

Gross hemolysis Reject
Gross icterus Reject

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 drugs most commonly prescribed 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



Cutoff concentrations by liquid chromatography- tandem mass spectroscopy:

Alprazolam: 10 ng/mL

Alpha-hydroxyalprazolam: 10 ng/mL

Chlordiazepoxide: 10 ng/mL

Clonazepam: 10 ng/mL

7-Aminoclonazepam: 10 ng/mL

Diazepam: 10 ng/mL

Nordiazepam: 10 ng/mL

Midazolam: 10 ng/mL

Alpha-hydroxy midazolam: 10 ng/mL

Oxazepam: 10 ng/mL

Temazepam: 10 ng/mL

Clobazam: 10 ng/mL

N-Desmethylclobazam by LC-MS/MS: 10 ng/mL

Flunitrazepam: 10 ng/mL

7-Aminoflunitrazepam: 10 ng/mL

Flurazepam: 10 ng/mL

2-Hydroxy ethyl flurazepam: 10 ng/mL

Lorazepam: 10 ng/mL

Prazepam: 10 ng/mL

Triazolam: 10 ng/mL

Alpha-hydroxy triazolam: 10 ng/mL

Zolpidem: 10 ng/mL

Zolpidem phenyl-4-carboxylic acid: 10 ng/mL


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


-Alpha-hydroxyalprazolam (metabolite of alprazolam)



-7-Aminoclonazepam (metabolite of clonazepam)

-Diazepam (separate prescribable drug and metabolite of medzazepam)

-Nordiazepam (metabolite of clorazepate, halazepam, prazepam, diazepam and medazepam)


-Alpha-hydroxy midazolam (metabolite of midazolam)

-Oxazepam (separate prescribable drug and metabolite of clorazepate, halazepam, prazepam, medazepam, temazepam, and diazepam)

-Temazepam (separate prescribable drug and metabolite of medazepam and diazepam)


-N-Desmethylclobazam (metabolite of clobazam)


-7-Aminoflunitrazepam (metabolite of flunitrazepam)


-2-Hydroxy ethyl flurazepam (metabolite of flurazepam)




-Alpha-hydroxy triazolam (metabolite of triazolam)


-Zolpidem phenyl-4-carboxylic acid (metabolite of zolpidem)


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.


No significant cautionary statements

Clinical Reference

1. Gudin JA, Mogali S, Jones JD, Comer SD: Risks, management, and monitoring of combination of opioid, benzodiazepines, and/or alcohol use. Postgrad Med. 2013 Jul;125(4):115-130. doi: 10.3810/pgm.2013.07.2684

2. Manchikanti L, Abdi S, Atluri S, et al: American Society of Interventional Pain Physicians (ASIPP) guidelines for responsible opioid prescribing in chronic non-cancer pain: Part 2--guidance. Pain Physician. 2012 Jul;15(3 Supp):S67-116

3. Barkin RL: In: Baselt RC, ed. Disposition of Toxic Drugs and Chemicals in Man. 8th ed. Biomedical Publications; 2008

4. Langman LJ, Bechtel LK, Meier BM, Holstege C: Clinical toxicology. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:1328-1333

Method Description

Benzodiazepines are extensively metabolized by the liver and subsequently exist in the urine primarily as conjugated esters (-glucuronides). The conjugated metabolites are cleaved during a mild hydrolysis utilizing the enzyme glucuronidase. Stable isotope forms of the compounds are added as internal standards to account for extraction losses. An aliquot of the hydrolyzed sample is diluted and the analytes are separated by liquid chromatography tandem mass spectroscopy (LC-MS/MS) and analyzed by multiple reaction monitoring.(Unpublished Mayo method)

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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 US Food and Drug Administration.

CPT Code Information




G0480 (if appropriate)

LOINC Code Information

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


Result ID Test Result Name Result LOINC Value
608256 Alprazolam by LC-MS/MS 59615-5
608257 Alpha-Hydroxyalprazolam by LC-MS/MS 16348-5
608258 Chlordiazepoxide by LC-MS/MS 20522-9
608259 Clonazepam by LC-MS/MS 16229-7
608260 7-aminoclonazepam by LC-MS/MS 51776-3
608261 Diazepam by LC-MS/MS 16227-1
608262 Nordiazepam by LC-MS/MS 16228-9
608263 Midazolam by LC-MS/MS 16233-9
608264 Alpha-Hydroxy Midazolam by LC-MS/MS 59590-0
608265 Oxazepam by LC-MS/MS 16201-6
608266 Temazepam by LC-MS/MS 20559-1
608267 Clobazam by LC-MS/MS 59635-3
608268 N-Desmethylclobazam by LC-MS/MS 97160-6
608269 Flunitrazepam by LC-MS/MS 20528-6
608270 7-aminoflunitrazepam by LC-MS/MS 51777-1
608271 Flurazepam by LC-MS/MS 16231-3
608272 2-Hydroxy Ethyl Flurazepam by LC-MS/MS 97159-8
608273 Lorazepam by LC-MS/MS 17088-6
608274 Prazepam by LC-MS/MS 17479-7
608275 Triazolam by LC-MS/MS 16232-1
608276 Alpha-Hydroxy Triazolam by LC-MS/MS 49876-6
608277 Zolpidem by LC-MS/MS 72770-1
608278 Zolpidem Phenyl-4-Carboxylic acid by LC-MS/MS 72768-5
608448 Benzodiazepines Interpretation 16195-0

NY State Approved


Day(s) Performed

Tuesday through Friday, Sunday

Report Available

3 to 6 days
UnityPoint Health Peoria Additional Information:


Benzodiazapines Urn Screen w/reflex
Benzodiazepines, S/P, Quant
Benzodiazepines, Urn, Quant