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Test Code DIA Diazepam and Nordiazepam, Serum

Additional Codes

CNE Order Code: Diazepam

Test Down Notes

Effective December 14, 2023:  This test is temporarily unavailable due to analytic issues.  The downtime is expected to be >30 days.  Order ZW86 (1501SP) as an alternate.  See test notification here.

Reporting Name

Diazepam and Nordiazepam, S

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


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.


Specimen Minimum Volume

0.3 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reference Values

Therapeutic concentrations

Diazepam and Nordiazepam: 200-2,500 ng/mL

Day(s) Performed

Monday, Wednesday

CPT Code Information

80299

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DIA Diazepam and Nordiazepam, 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

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.

Report Available

3 to 7 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.