Test ID DIA Diazepam and Nordiazepam, Serum
Test Down Notes
This test is temporarily unavailable due to instrumentation issues. As an alternate, order ZW86 (1501SP). For additional details, see test update here.
Specimen Required
Collection Container/Tube: Red top (Serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial.
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Neurology Specialty Testing Client Test Request (T732)
-Therapeutics Test Request (T831)
Secondary ID
8629Useful For
Assessing compliance
Monitoring for appropriate therapeutic level
Assessing diazepam toxicity
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Diazepam and Nordiazepam, SSpecimen Type
Serum RedSpecimen Minimum Volume
0.3 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Serum Red | Refrigerated (preferred) | 14 days |
Ambient | 14 days | |
Frozen | 14 days |
Clinical Information
Diazepam, a benzodiazepine derivative, is an anxiolytic agent that reduces neuronal depolarization resulting in decreased action potentials. It enhances the action of gamma-aminobutyric acid (GABA) by tightly binding to A-type GABA receptors, thus opening the membrane channels, and allowing the entry of chloride ions. It is also used as a muscle relaxant, procedural sedation agent, and sedative-hypnotic agent to treat withdrawal states (ie, ethanol), along with other conditions (seizures).
Diazepam is metabolized to several metabolites in the liver, including temazepam, oxazepam, and nordiazepam (desmethyldiazepam), and the clearance of the drug is reduced considerably in older individuals and in patients with hepatic disease.
Therapeutic assessment typically includes measurement of both the parent drug (diazepam) and the active metabolite (nordiazepam).
Reference Values
Therapeutic concentrations
Diazepam and Nordiazepam: 200-2,500 ng/mL
Cautions
No significant cautionary statements
Day(s) Performed
Monday, Wednesday
Report Available
3 to 7 daysPerforming Laboratory

Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80346
G0480 (if appropriate)