Synonyms
- GP 47680
- Trileptal®
Test Includes
Analysis of active metabolite, 10-hydroxy carbamazepine (MHD)
Expected 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.
Related Documents
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
Transfer separated serum or plasma to a plastic transport tube.
Storage Instructions
Maintain specimen at room temperature.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Causes for Rejection
Gross lipemia; hemolysis; icteric specimen; gel-barrier tube
Test Details
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.
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Reference Interval
10−35 μg/mL
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
Footnotes
1. Bourgeois BF. Pharmacokinetic properties of current antiepileptic drugs. What improvements are needed? Neurology. 2000; 55(Suppl 3):S11-S16. 11147563
2. Wheless JW. Using the new antiepilepsy drugs in children. J Child Neurol. 2002 Jan; 17(Suppl 1):S58-S64. 11918465
References
Lensmeyer GL, Gidal BE, Wiebe DA. Optimized high-performance liquid chromatographic method for determination of lamotrigine in serum with concomitant determination of phenytoin, carbamazepine, and carbamazepine epoxide. Ther Drug Monit. 1997 Jun; 19(3):292-300. 9200770
Physicians' Desk Reference. 66th ed. Montvale, NJ: Thompson PDR; 2012.
Souppart C, Decherf M, Humbert H, Maurer G. Development of a high throughput 96-well plate sample preparation method for the determination of Trileptal (oxcarbazepine) and its metabolites in human plasma. J Chromatogr B Biomed Sci Appl. 2001 Oct 5; 762(1):9-15. 11589463
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 |
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