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Test Code CARBG Carbamazepine-10,11-Epoxide, Serum

Additional Codes


Powerchart: Carbamazepine 10 11 Epoxide


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

Method Name

CARTA: Homogeneous Microparticle Agglutination Immunoassay

1011E: High-Performance Liquid Chromatography (HPLC)

Reporting Name

Carbamazepine-10,11-Epoxide, S

Specimen Type

Serum Red

Specimen Required

Container/Tube: Red top

Specimen Volume: 2 mL

Collection Instructions: Draw blood 12 hours (trough value) after last dose.

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
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


Therapeutic: 4.0-12.0 mcg/mL

Critical value: ≥15.0 mcg/mL



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 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

80156-Carbamazepine, Tot, S


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


If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.