Test Code CARF Carbamazepine, Free, Serum
Reporting Name
Carbamazepine, Free, SUseful For
Monitoring unbound or free carbamazepine levels in patients where the total carbamazepine result is within the therapeutic range, but the patient is experiencing side effects
Monitoring carbamazepine (free) therapy in patients who are uremic
Specimen Type
Serum RedSpecimen Required
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
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 |
Reference Values
Therapeutic concentration: 1.0-3.0 mcg/mL
Critical value: ≥4.0 mcg/mL
Day(s) Performed
Monday through Sunday
Performing Laboratory

Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were 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
80157
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
CARF | Carbamazepine, Free, S | 3433-0 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
CARF | Carbamazepine, Free, S | 3433-0 |
Method Name
Ultrafiltration followed by Homogeneous Microparticle Agglutination Immunoassay
Report Available
Same day/1 dayForms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.