Diazepam and Nordiazepam
Also known as: DIAZ
Use
This test is used to optimize dosing and monitor patient adherence to diazepam and its primary metabolite nordiazepam. Monitoring therapeutic levels helps ensure effective medication management and prevent potential adverse effects such as drowsiness, fatigue, ataxia, and muscle weakness. Diazepam is typically prescribed for anxiety, muscle spasms, and seizures, making it important to maintain appropriate dosage levels for effective treatment.
Special Instructions
The specimen should be collected pre-dose at steady state concentration (trough level). Use grey top (potassium oxalate/sodium fluoride) tubes, or when necessary, plain red, green (sodium heparin), lavender (K2 or K3EDTA), or pink (K2EDTA) tubes are acceptable. Ensure serum or plasma separation from cells happens within 2 hours of collection.
Limitations
The measurement of diazepam and nordiazepam levels may not fully reflect the extent of CNS pharmacological activity, as other active metabolites not directly measured may also be present. Analytical interferences can occur if samples are not processed promptly or if the specified specimen types and tubes are not used. Repeated freeze/thaw cycles must be avoided as they may degrade analyte stability. Gel separator tubes are unacceptable, as are whole blood or plasma collected using sodium citrate light blue tops.
New York Approved
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 3548-5
- 3537-8
Result Turnaround Time
1-7 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
1 mL
Container
Plain red, grey, green (sodium heparin), lavender (K2 or K3EDTA), or pink (K2EDTA) tubes
Collection Instructions
Collect predose (trough) draw at steady state concentration in the specified tube types. Separate serum or plasma from cells within 2 hours.
Patient Preparation
Timing of specimen collection: Predose (trough) draw at steady state concentration.
Storage Instructions
Store and transport refrigerated.
Causes for Rejection
Gel separator tubes, plasma or whole blood in light blue (sodium citrate) tubes, hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 week |
| Refrigerated | 2 weeks |
| Frozen | 3 years |