Clozapine

Test Code

CLZPN

Alias/See Also

LAB3038

CPT Codes
<p>80159</p>

Includes

Clozapine and Norclozapine

Preferred Specimen

Specimen Type: Serum Red

Collection Container/Type: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 2 mL

Specimen Type: Plasma

Collection Container/Type

Preferred: Lavender top (EDTA)

Acceptable: Green top (sodium or lithium heparin)

Specimen Volume: 2 mL

Minimum Volume

1 mL

Other Acceptable Specimens

Plasma collected in an: EDTA (lavender-top), or sodium or lithium heparin (green-top) tube

Transport Container

Plastic screw-cap vial

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

Room temperature: 24 hours

Refrigerated: 5 days

Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis • Gel barrier/Serum Separator Tube (SST ®)

Methodology

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

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

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 the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Mon-Sat; Report available: 2 days

Report Available

2 days

Reference Range

Norclozapine

25-400 mcg/L

Clozapine
The therapeutic response begins to appear at 100 mcg/L
Refractory schizophrenia appears to require a therapeutic concentration of at least 350 mcg/L (trough, at steady state).
Toxic range: >900 mcg/L

Clinical Significance

Clozapine is an atypical antipsychotic agent. Norclozapine has minimal therapeutic activity.

Performing Laboratory
Quest Diagnostics Nichols Institute 14225 Newbrook Drive Chantilly, VA 20153

Last Updated: February 17, 2023

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.