Oxcarbazepine (Trileptal®), Serum
| Oxcarbazepine (Trileptal®), Serum | | | |
| Number | | 716928 |
| CPT | | 82491 |
| Synonyms | | GP 47680 ; Trileptal® |
| Test Includes | | Analysis of active metabolite, 10-hydroxy carbamazepine (MHD) |
| Specimen | | Serum or plasma |
| Volume | | 1 mL |
| Minimum Volume | | 0.3 mL |
| Container | | Red-top tube or lavender-top (EDTA) tube |
Collection | | Transfer separated serum or plasma to a plastic transport
tube. Do not use a gel-barrier tubes; 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.
Trough: Immediately prior to next dose.
Steady-state levels are reached within 2-3 days in patients
taking oxcarbazepine twice daily. |
| Storage Instructions | | Refrigerate at 2°C to 8°C if specimen is not tested immediately. |
| Causes for Rejection | | Gross lipemia; hemolysis; icteric specimen; gel-barrier tube |
| Reference Interval | | 10-35 μg/mL |
| 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 4 and 16. |
| Limitations | | Clinically-significant hyponatremia (sodium <125 mmol/L) can develop during oxcarbazepine use. This generally occurs during the first 3 months of treatment. |
| Methodology | | High-pressure liquid chromatography (HPLC) with UV detection |
| Additional Information | | Oxcarbazepine is the prodrug for its active metabolite, 10-hydroxy-carbamazepine (MHD). MHD reaches maximal serum concentrations in 3-5 hours after oral ingestion and is 40% bound to protein. The elimination half-life is 8-15 hours.1 Co-administration of other antiepileptic drugs (eg, carbamazepine, phenytoin, phenobarbital, primidone) causes decreases in MHD serum levels.2 |
| 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;
19(3):292-300.
Physicians' Desk Reference, 55th ed, Montvale,
NJ: Medical Economics Press. 2001; 2223-2228.
Souppart C, Decherf M, Humbert H. et al. 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; 762(1):9-15. |
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