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Epic Test Code LAB3761 Chlordiazepoxide and Metabolite, Serum

Additional Codes

MML Code: CDP

 

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, (1080SP) as an alternate.  See test notification here.

NY State Approved

Yes

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Reporting Name

Chlordiazepoxide and metabolite, S

Method Name

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

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Refrigerated (preferred) 14 days LIGHT PROTECTED
  Frozen  14 days LIGHT PROTECTED
  Ambient  24 hours LIGHT PROTECTED


Shipping Instructions


Ship specimen in amber vial to protect from light.



Specimen Required


Supplies: Amber Frosted Tube, 5 mL (T915)

Collection Container/Tube: Red top

Submission Container/Tube: Amber vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into amber vial within 2 hours of collection.


Bassett Healthcare Network Clinical Laboratories Note:

Blood Tube Draw Volume
Min 50% draw volume  

 

Specimen Type

Serum Red

Specimen Minimum Volume

0.3 mL

Reference Values

Therapeutic concentration:

Chlordiazepoxide: 400-3,000 ng/mL

Nordiazepam: 100-500 ng/mL

Report Available

2 to 7 days

Day(s) Performed

Monday, Wednesday

CPT Code Information

80299

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Useful For

Monitoring chlordiazepoxide therapy

 

Assessing toxicity

Clinical Information

Chlordiazepoxide (Librium) is a benzodiazepine widely used in the treatment of anxiety, alcohol withdrawal symptoms, and as a premedication for anesthesia. The mechanism of action of all benzodiazepines remains unclear. However, it is known that benzodiazepines facilitate gamma-amino butyric acid (GABA)-mediated neurotransmission in the brain. Benzodiazepines most likely facilitate the inhibitory presynaptic or postsynaptic reactions of GABA.

 

Chlordiazepoxide is metabolized to long-acting metabolites in the liver to the active metabolite nordiazepam (desmethyldiazepam), and the clearance of the drug is reduced considerably in the elderly and in patients with hepatic disease.

 

Therapeutic assessment should include measurement of both the parent drug (chlordiazepoxide) and the active metabolite (nordiazepam).

 

Since chlordiazepoxide has a wide therapeutic index and toxicity is dose-dependent, routine drug monitoring is not indicated in all patients

Interpretation

Chlordiazepoxide and nordiazepoxide combined concentrations above 5000 ng/mL have been associated with toxicity.

Cautions

The specimen must be protected from light.

Specimen Retention Time

14 days

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)