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Test Code LAB7543 Diazepam and Metabolites, Serum

Additional Codes

DIA

Useful For

Assessing compliance

 

Monitoring for appropriate therapeutic level

 

Assessing diazepam toxicity

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum Red


Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Red top (Serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

Therapeutic concentrations

Diazepam: Not established

Diazepam and Nordiazepam: 100-2,500 ng/mL

 

Cutoff concentrations by liquid chromatography tandem mass spectrometry:

Diazepam: 10 ng/mL

Nordiazepam: 10 ng/mL

Oxazepam: 10 ng/mL

Temazepam: 10 ng/mL

Day(s) Performed

Wednesday

CPT Code Information

80299

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DIA Diazepam and metabolites, S 49044-1

 

Result ID Test Result Name Result LOINC Value
8629 Diazepam 3548-5
2475 Nordiazepam 3537-8
2459 Diazepam and Nordiazepam 16757-7
622868 Oxazepam 3886-9
622869 Temazepam 10343-2

Interpretation

For seizures:

Serum concentrations are not usually monitored during early therapy because response to the drug can be monitored clinically as seizure control. If seizures resume despite adequate therapy, another anticonvulsant must be considered.

 

Toxicity is commonly seen when diazepam plus nordiazepam concentrations exceed 3000 ng/mL. Adverse effects of benzodiazepines in therapeutic doses usually reflect the drug's pharmacology and include sedation, slurred speech, and ataxia. Respiratory depression/arrest may occur with large overdoses or following rapid intravenous injection with short-acting benzodiazepines.

Method Description

The internal standard mixture containing chlordiazepoxide-d5, diazepam-d5 , nordiazepam-d5, oxazepam-d5, and temazepam-d5 is added to serum samples, mixed, and centrifuged. The supernatant is diluted and injected on a liquid chromatography tandem mass spectrometer.(Unpublished Mayo method)

Report Available

3 to 7 days

Specimen Retention Time

14 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Method Name

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

Forms

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

Secondary ID

8629