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HelpOrder Code CLZ Clozapine, Serum
Useful For
Monitoring patient compliance of clozapine treatment
An aid to achieving desired serum levels
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Clozapine, SSpecimen Type
Serum RedOrdering Guidance
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Â
1. Collect specimen immediately before next scheduled dose.
2. Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
Additional Information: Therapeutic range (trough level) applies to specimens collected immediately prior to next dose.
Specimen Minimum Volume
0.6 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 7 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
Clozapine
Therapeutic range: 350-600 ng/mL
Norclozapine
Therapeutic range: Not well established
Clozapine + Norclozapine
Therapeutic range: Not well established
Method Description
Deuterated stable isotope of clozapine is added to the serum sample as an internal standard. Protein is precipitated from the mixture by the addition of acetonitrile. Clozapine, norclozapine, and the internal standard are extracted from the resulting supernatant by an online extraction utilizing high-throughput liquid chromatography. This is followed by conventional liquid chromatography and analysis on a tandem mass spectrometer equipped with a heated nebulizer ion source.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80159
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.