Test Details
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Result Turnaround Time
2 - 4 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
Analysis of active metabolite, 10-hydroxy carbamazepine (MHD)
Use
Oxcarbazepine is an antiepileptic drug, indicated for use as monotherapy or adjunctive therapy in the treatment of partial seizures in adults with epilepsy. It is used in adjunctive therapy in epileptic children between the ages of four and 16.
Limitations
Clinically significant hyponatremia (sodium <125 mmol/L) can develop during oxcarbazepine use. This generally occurs during the first three months of treatment.
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Footnotes
References
Custom Additional Information
Oxcarbazepine is the prodrug for its active metabolite, 10-hydroxy-carbamazepine (MHD). MHD reaches maximal serum concentrations in three to five hours after oral ingestion and is 40% bound to protein. The elimination half-life is 8 to 15 hours.1 Co-administration of other antiepileptic drugs (eg, carbamazepine, phenytoin, phenobarbital, primidone) causes decreases in MHD serum levels.2
Specimen Requirements
Specimen
Serum or plasma
Volume
1 mL
Minimum Volume
0.3 mL
Container
Red-top tube, lavender-top (EDTA) tube, or green-top (heparin) tube. Do not use a gel-barrier tube. The use of gel-barrier tubes is not recommended due to slow absorption of the drug by the gel. Depending on the specimen volume and storage time, the decrease in drug level due to absorption may be clinically significant.
Collection Instructions
Transfer separated serum or plasma to a plastic transport tube.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
10−35 μg/mL
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Gross lipemia; hemolysis; icteric specimen; gel-barrier tube
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 716928 | Oxcarbazepine (Trileptal),S | 35331-8 | 716930 | Oxcarbazepine | ug/mL | 35331-8 |
| Order Code | 716928 | |||||
| Order Code Name | Oxcarbazepine (Trileptal),S | |||||
| Order Loinc | 35331-8 | |||||
| Result Code | 716930 | |||||
| Result Code Name | Oxcarbazepine | |||||
| UofM | ug/mL | |||||
| Result LOINC | 35331-8 |