Test Code CARBG Carbamazepine-10,11-Epoxide, Serum
Useful For
Monitoring patients exhibiting symptoms of carbamazepine toxicity whose total serum carbamazepine concentration is within the therapeutic range, but who may be producing significant levels of the active metabolite epoxide, which can accumulate to concentrations equivalent to carbamazepine
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
CARTA | Carbamazepine, Tot, S | Yes | Yes |
1011E | Carb-10,11-Epoxide, S | No | Yes |
Reporting Name
Carbamazepine-10,11-Epoxide, SSpecimen Type
Serum RedSpecimen Required
Collection Container/Tube: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions:
1. Draw blood 12 hours (trough value) after last dose.
2. Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Serum Red | Refrigerated (preferred) | 7 days |
Frozen | 28 days | |
Ambient | 48 hours |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Reference Values
CARBAMAZEPINE, TOTAL
Therapeutic: 4.0-12.0 mcg/mL
Critical value: ≥15.0 mcg/mL
CARBAMAZEPINE-10,11-EPOXIDE
Therapeutic concentration: 0.4-4.0 mcg/mL
Toxic concentration: ≥8.0 mcg/mL
Day(s) Performed
CARTA: Monday through Sunday
1011E: Tuesday
Report Available
Same day/1 to 7 daysSpecimen Retention Time
CARTA: 1 week ; 1011E: 2 weeksPerforming Laboratory

CPT Code Information
80156-Carbamazepine, Tot, S
80161-Carbamazepine-10,11-Epoxide
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
CARBG | Carbamazepine-10,11-Epoxide, S | 50337-5 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
7467 | Carb-10,11-Epoxide, S | 9415-1 |
CARTA | Carbamazepine, Tot, S | 3432-2 |
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.