Epic Test Code LAB468 Diazepam and Nordiazepam, Serum
Additional Codes
MML Code: DIA
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.
NY State Approved
YesPerforming Laboratory
Mayo Clinic Laboratories in RochesterReporting Name
Diazepam and Nordiazepam, SMethod Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Refrigerated (preferred) | 14 days | |
Ambient | 14 days | ||
Frozen | 14 days |
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.
Blood Tube Draw Volume
Min 50% draw volume
Specimen Type
Serum RedSpecimen Minimum Volume
0.3 mL
Reference Values
Therapeutic concentrations
Diazepam and Nordiazepam: 200-2,500 ng/mL
Report Available
3 to 7 daysDay(s) Performed
Monday, Wednesday
CPT Code Information
80299
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Useful For
Assessing compliance
Monitoring for appropriate therapeutic level
Assessing diazepam toxicity
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).
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.
Cautions
No significant cautionary statements
Specimen Retention Time
14 daysForms
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)