Carbamazepine Epoxide & Total Drug Level
Label Mnemonic: CBZ-EP
Epic Lab Code: LAB21
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
Specimen Instructions:
Timing of specimen collection: Pre-dose (trough) draw - At steady state concentration.

Separate serum from cells within two hours of collection.
Collection Medium:
Red top tube 5 mL (Clot Activator)
Preferred Minimum: 1.0 mL serum
Rejection Criteria:
Whole blood. Gel separator tubes, light blue (citrate), or yellow (SPS or ACD solution).
Turn Around Time:
5 days upon receipt at reference laboratory
Reference Range:
Components Therapeutic Range Carbamazepine-10, 11 Epoxide Not well established Toxic: Greater than 15.0 μg/mL Total Carbamazepine 4.0-12.0 μg/mL Toxic: Greater than 15.0 μg/mL
Interpretive Data:
A proposed therapeutic range is 0.4-4 μg/mL. The metabolite, Carbamazepine-10, 11-Epoxide, has anticonvulsant activity to the parent drug.
Quantitative Liquid Chromatography-Tandem Mass Spectrometry/Quantitative Enzyme Multiplied Immunoassay Technique
CPT Code:
Carbamazepine, Total, 80156; Carbamazepine, Epoxide, 80157
See also:
Carbamazepine, Plasma