Home
HelpMayo Test ID CDP Chlordiazepoxide and Metabolites, Serum
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 (serum get/SST are not acceptable)
Submission Container/Tube: Amber vial
Specimen Volume: 1 mL
Collection Instructions: Within 2 hours of collection, centrifuge and aliquot serum into an amber vial.
Useful For
Monitoring chlordiazepoxide therapy
Assessing toxicity
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Chlordiazepoxide and metabolites, SSpecimen Type
Serum RedSpecimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Refrigerated (preferred) | 28 days | LIGHT PROTECTED |
| Ambient | 28 days | LIGHT PROTECTED | |
| Frozen | 28 days | LIGHT PROTECTED |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Clinical Information
Chlordiazepoxide (Librium) is a benzodiazepine widely used in the treatment of anxiety and alcohol withdrawal symptoms, as well 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 metabolites nordiazepam (desmethyldiazepam) and oxazepam, and the clearance of the drug is reduced considerably in older adults and in patients with hepatic disease.
Therapeutic assessment should include measurement of both the parent drug (chlordiazepoxide) and the primary active metabolite (nordiazepam), with a proposed combined chlordiazepoxide and nordiazepam reference interval of 700 to 1000 ng/mL. However, therapeutic and toxic concentrations can vary greatly and should be interpreted in the full clinical context of the patient. Since chlordiazepoxide has a wide therapeutic index and toxicity is dose-dependent, routine drug monitoring is not indicated in all patients.
Reference Values
Therapeutic concentration:
Chlordiazepoxide: 400-3,000 ng/mL
Cutoff concentrations by liquid chromatography tandem mass spectrometry:
Chlordiazepoxide: 10 ng/mL
Nordiazepam: 10 ng/mL
Oxazepam: 10 ng/mL
Interpretation
Combined concentrations of chlordiazepoxide and nordiazepam above 5000 ng/mL have been associated with toxicity.
Cautions
The specimen must be protected from light.
Clinical Reference
1. Langman LJ, Bechtel LK, Holstege CP. Clinical toxicology. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 43
2. Burtis CA, Ashwood ER, Bruns DE, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. WB Saunders Company; 2011:1109-1188
3. Hiemke C, Bergemann N, Clement HW, et al. Consensus guidelines for therapeutic drug monitoring in neuropsychopharmacology: Update 2017. Pharmacopsychiatry. 2018;51(1-02):9-62
4. Adeli K, Higgins V, Bohn MK. Reference information for the clinical laboratory. In: In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:1390-1470
Method Description
The internal standard mixture containing chlordiazepoxide-d5, diazepam-d5 , nordiazepam-d5, oxazepam-d5, and temazepam-d5 is added to serum samples, mixed, and centrifuged. The supernatant is diluted and injected on a liquid chromatography tandem mass spectrometer.(Unpublished Mayo method)
Day(s) Performed
Wednesday
Report Available
2 to 7 daysSpecimen Retention Time
14 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
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
80299
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CDP | Chlordiazepoxide and metabolites, S | 33060-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8610 | Chlordiazepoxide | 3457-9 |
| 37321 | Nordiazepam | 3537-8 |
| 622870 | Oxazepam | 3886-9 |