Test Code CARFT Carbamazepine, Free and Total, Serum
Useful For
Monitoring carbamazepine (free and total) therapy in patients who are uremic
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
CARTA | Carbamazepine, Tot, S | Yes | Yes |
CARF | Carbamazepine, Free, S | Yes | Yes |
Method Name
CARF: Ultrafiltration Followed by Homogeneous Microparticle Agglutination Immunoassay
CARTA: Homogeneous Microparticle Agglutination Immunoassay
Reporting Name
Carbamazepine, Free and Total, SSpecimen Type
Serum RedSpecimen Required
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
CARBAMAZEPINE, TOTAL
Therapeutic: 4.0-12.0 mcg/mL
Critical value: ≥15.0 mcg/mL
CARBAMAZEPINE, FREE
Therapeutic: 1.0-3.0 mcg/mL
Critical value: ≥4.0 mcg/mL
Cautions
Fresh serum with normal protein content is required for optimal analysis.
Specimens subjected to significant heat or other factors that cause protein denaturation demonstrate an artifactually increased free carbamazepine.
If hemolysis, lipemia, or icterus exceed the analytical interference threshold, the testing will be canceled.
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 dayPerforming 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
80156
80157
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
CARFT | Carbamazepine, Free and Total, S | 34545-4 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
CARF | Carbamazepine, Free, S | 3433-0 |
CARTA | Carbamazepine, Tot, S | 3432-2 |
NY State Approved
YesForms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.