Clorazepate (Tranxene®)

Test Code

Quest Code

CPT Codes
80346 (HCPCS: G0480)

Preferred Specimen
2 mL serum collected in a red-top tube (no gel)

Minimum Volume
1 mL

Other Acceptable Specimens
Plasma collected in: EDTA (lavender-top) tube or ACD (yellow-top) tube

Note: Assayed as its primary metabolite, Nordiazepam.

Transport Container
Plastic polypropylene tubes

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Serum separator tube (SST®)

Chromatography/Mass Spectrometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Report Available
1 to 8 Day(s)

Reference Range
Nordiazepam 100-500 ng/mL

Clinical Significance
Orally administered clorazepate is rapidly decarboxylated to its metabolite, nordiazepam. There is essentially no circulating patent drug. Nordiazepam elimination half-life is about 40 to 50 hours. Plasma levels of nordiazepam increase proportionally with clorazepate dose and show moderate accumulation with repeated administration.

Performing Laboratory
Quest Diagnostics Nichols Institute
27027 Tourney Road
Valencia, CA 91355-5386

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.