Test Catalog

Test Id : CARTA

Carbamazepine, Total, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Monitoring therapy


Determining compliance


Assessing toxicity

Method Name
A short description of the method used to perform the test

Homogeneous Microparticle Agglutination Immunoassay

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Carbamazepine, Tot, S

Lists additional common names for a test, as an aid in searching

Carbatrol (Carbamazepine)

Carbamazepine (Carbatrol, Tegretol)

Tegretol (Carbamazepine)

Specimen Type
Describes the specimen type validated for testing

Serum Red

Ordering Guidance

This test measures carbamazepine only. For assessment of its active metabolite, carbamazepine-10,11-epoxide, which is the predominant form in children, order CARBG / Carbamazepine-10,11-Epoxide, Serum)

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube: Red top

Specimen Volume: 0.5 mL

Submission Container/Tube: Plastic vial

Collection Instructions: Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.


If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Neurology Specialty Testing Client Test Request (T732)

-Therapeutics Test Request (T831)

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.25 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Red Refrigerated (preferred) 7 days
Frozen 28 days
Ambient 48 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Monitoring therapy


Determining compliance


Assessing toxicity

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Carbamazepine (Tegretol) is used in the control of partial seizures with both temporal lobe and psychomotor symptoms as well as for generalized tonic-clonic seizures. It is also used for analgesia in trigeminal neuralgia.


Carbamazepine exhibits a volume of distribution of 1.4 L/kg with an elimination half-life of 15 hours. Protein binding averages 70%.


Carbamazepine-10,11-epoxide (CBZ10-11) is an active metabolite that represents the predominant form of the drug in children. The volume of distribution of CBZ10-11 is 1.1 L/kg, and the half-life is 5 to 8 hours.


Aplastic anemia and agranulocytosis are rare side effects of treatment with carbamazepine; baseline hematologic data should be documented before treatment is initiated.


Toxicity associated with carbamazepine overdose occurs when the blood level is 15.0 mcg/mL or higher and is typified by irregular breathing, muscle irritability, and hyperreflexia; followed by hyporeflexia, tachycardia, hypotension, and impaired consciousness with coma in severe toxicity. The higher the blood level, the more severe the symptoms.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Therapeutic: 4.0-12.0 mcg/mL

Critical value: > or =15.0 mcg/mL

Provides information to assist in interpretation of the test results

Dosage adjustments are usually guided by monitoring blood levels. Most patients respond well when the serum concentration is in the range of 4.0 to 12.0 mcg/mL. Toxicity often occurs when levels are greater than or equal to 15.0 mcg/mL.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Carbamazepine-10,11-epoxide (CBZ10-11) is not reported. A separate orderable test for this active metabolite is available (CARBG / Carbamazepine-10,11-Epoxide, Serum). Optimal response occurs when the CBZ10-11 serum level is in the range of 0.4 to 4.0 mcg/mL.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Cereghino JJ, Meter JC, Brock JT, Penry JK, Smith LD, White BG: Preliminary observations of serum carbamazepine concentration in epileptic patients. Neurology. 1973 Apr;23(4):357-366. doi: 10.1212/wnl.23.4.357

2. Patsalos PN, Berry DJ, Bourgeois BF, et al: Antiepileptic drugs--best practice guidelines for therapeutic drug monitoring: a position paper by the subcommission on therapeutic drug monitoring, ILAE Commission on Therapeutic Strategies. Epilepsia. 2008 Jul;49(7):1239-1276. doi: 10.1111/j.1528-1167.2008.01561.x

3. Scheuer ML, Pedley TA: The evaluation and treatment of seizures. N Engl J Med. 1990 Nov 22;323(21):1468-1474. 10.1056/NEJM199011223232107

4. Milone MC, Shaw LM: Therapeutic Drug Monitoring. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Fundamentals of Clinical Chemistry and Molecular Diagnostics. 8th ed. Saunders; 2019:549

5. Patsalos PN, Zugman M, Lake C, James A, Ratnaraj N, Sander JW. Serum protein binding of 25 antiepileptic drugs in a routine clinical setting: a comparison of free non-protein-bound concentrations. Epilepsia. 2017 Jul;58(7):1234-1243. doi: 10.1111/epi.13802

Method Description
Describes how the test is performed and provides a method-specific reference

The ONLINE TDM Carbamazepine Gen.4 assay is a homogeneous microparticle agglutination immunoassay. It is a 2-reagent system used for the detection of carbamazepine in serum. Kinetic interaction of microparticles will be measured using automated analyzers. In this technology biotinylated drug hapten attached to streptavidin coated latex beads serves as the binding partner to anti-carbamazepine antibody. A competitive reaction to a limited amount of specific anti-carbamazepine antibody takes place between the latex bound hapten and free carbamazepine in the serum sample. A decrease in the apparent signal is proportional to the amount of drug present in the sample.(Package insert: ONLINE TDM Carbamazepine Gen.4. Roche Diagnostics; 04/2016)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 day

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
CARTA Carbamazepine, Tot, S 3432-2
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
CARTA Carbamazepine, Tot, S 3432-2

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports