Skip to Content
UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Carbamazepine and Metabolite

Test Code(s): CARB / HCCARB

CPT Code(s): 80156, 80157

Test Description: Test Component:

Carbamazepine and carbamazepine-10,11-epoxide.

Methodology: Liquid Chromatography

Clinical Significance: Anticonvulsant

Days Performed: Mon-Fri, dayshift.

Turnaround Time: Routine: 24 hours.

Specimen Requirements

Specimen: Blood

Collection Instructions: Collect serum sample 15-30 minutes prior to the morning dose.

Collection Container: Preferred: Red top

Collection Volume: Preferred: 3 mL
Pediatrics: 1 mL

Sample Analyzed: Serum

Volume Required: Preferred: 1 mL
Pediatrics: 0.3 mL

Specimen Processing: Centrifuge. Transfer cell-free serum to plastic vial. Refrigerate.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.

Unacceptable Criteria: Specimens collected in red cap with yellow ring (SST) tubes are not acceptable.

Stability: Ambient: 2 days
Refrigerated: 3 days
Frozen: 14 days


Interpretive Guidelines:
Generally effective therapeutic concentration:  
18 years and up:  


4.0-12.0 mcg/mL 


Carbamazepine-10,11-epoxide metabolite is active and should be 20-30% of parent compound. Carbamazepine-10,11-epoxide level greater than 50% of parent drug level may be toxic.

Critical Calls: View

Additional Information:

Result of "BELOW" indicates that the result is below the method detection limit of 0.5 mcg/mL. Carbamazepine results greater than 15.0 mcg/mL will be called. Carbamazepine-10,11-epoxide is the principle metabolite of carbamazepine and is an active metabolite whose plasma concentration may be increased in the presence of enzyme inducers, valproic acid, or felbamate.


This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories.  This test meets the standards for clinical testing.  This test should not be regarded as investigational or for research use.  The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.

Tegretol 10,11-epoxide carbamazepine

Back to Lab Test Directory Index