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HelpTest ID OMHC Oxcarbazepine Metabolite (MHC), Serum
Useful For
Monitoring serum concentration during oxcarbazepine therapy
Assessing compliance
Assessing potential toxicity
Method Name
High-Turbulence Liquid Chromatography Mass Spectrometry (HTLC-MS/MS)
Reporting Name
Oxcarbazepine Metabolite (MHC), SSpecimen Type
SerumContainer/Tube:
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 0.2 mL
Collection Instructions:
1. Draw specimen immediately before next scheduled dose.
2. Spin down within 2 hours of draw.
Forms: If not ordering electronically, complete, print, and send a Neurology Test Request Form-General (T732) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/neurology-request-form.pdf)
Specimen Minimum Volume
0.1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 14 days |
| Ambient | 14 days | |
| Frozen | 14 days |
Clinical Information
Oxcarbazepine (OCBZ) is approved as monotherapy and adjunctive therapy for partial seizures with and without secondary generalized seizures in adults and as adjunctive therapy for partial seizures in children. In humans, OCBZ is a prodrug that is almost immediately and completely metabolized to 10-hydroxy-10,11-dihydrocarbamazepine, known as monohydroxycarbamazepine (MHC), an active metabolite that is responsible for OCBZ's therapeutic effect. The elimination half-life is 1 to 2.5 hours for OCBZ and 8 to 10 hours for MHC. The therapeutic range (3–35 mcg/mL) is based on concentrations of the metabolite, not the parent drug; this assay measures the metabolite only.
In clinical practice, the OCBZ dosage should be individually adjusted for each patient to achieve the desired therapeutic response. Toxicity associated with OCBZ includes hyponatremia, dizziness, somnolence, diplopia, fatigue, nausea, vomiting, ataxia, abnormal vision, abdominal pain, tremor, dyspepsia, and abnormal gait. These toxicities may be observed when blood concentrations are in the therapeutic range.
Reference Values
Oxcarbazepine metabolite: 3-35 mcg/mL
Cautions
Toxic levels have not been well established.
This test cannot be performed on whole blood. Serum must be separated from cells within 2 hours of draw.
Day(s) Performed
Tuesday through Saturday; 12 a.m., Saturday; 1 p.m.
Report Available
Same day/1 dayPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
80183