Test Code CARFT Carbamazepine, Free and Total, Serum
Useful For
Monitoring carbamazepine (free and total) therapy in uremic patients
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 RedShipping Instructions
Â
Specimen Required
Container/Tube: Red top
Specimen Volume: 2 mL
Collection Instructions: Tubes should be centrifuged and aliquoted within 2 hours of collection.
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 |
Clinical Information
Carbamazepine (Tegretol) is an effective treatment for complex partial seizures, with or without generalization to tonic-clonic seizures. It is frequently administered in conjunction with other antiepileptic agents, such as phenytoin and valproic acid.
Under normal circumstances, the carbamazepine that circulates in blood is 75% protein bound. In severe uremia, carbamazepine may be displaced from protein, resulting in a higher free (unbound) fraction of the drug circulating in blood. Since neurologic activity and toxicity are directly related to the circulating free fraction of drug, adjustment of dosage based on knowledge of the free carbamazepine level may be useful in patients with severe uremia.
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
Day(s) and Time(s) Performed
Monday through Sunday; Continuously
Analytic Time
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 U.S. Food and Drug Administration.CPT Code Information
80156-Carbamazepine, Total, S
80157-Carbamazepine, Free, S
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.