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Carbamazepine, Free and Total, Serum or Plasma
2011763
Ordering Recommendation

Optimize drug therapy and monitor patient adherence.

Mnemonic
CARB FT
Methodology
Quantitative Enzyme Multiplied Immunoassay Technique
Performed
Mon, Wed, Fri
Reported
1-5 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
 
Collect
Serum Pre-dose (Trough) Draw - At a Steady State Concentration in Plain Red. 
Specimen Preparation
Separate from cells ASAP or within 2 hours of collection. Transfer 2 mL serum to an ARUP Standard Transport Tube. (Min: 1 mL) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
Whole Blood, Citrated Plasma. Tubes that contain liquid anticoagulant.or Serum separator tube (SST). 
Remarks
Please indicate in the supplied fields:
1.  Dose - List drug amount and include the units of measure
2.  Route - List the route of administration (IV, oral, etc.)
3.  Dose Frequency - Indicate how often the dose is administered (per day, per week, as needed, etc.)
4.  Type of Draw - Indicate the type of blood draw (Peak, Trough, Random, etc.) 
Stability
Ambient: 5 days; Refrigerated: 5 days; Frozen: 3 months 
Reference Interval
Effective November 16, 2015
Test Number
Components
Reference Interval
 Total CarbamazepineTherapeutic Range: 4.0-12.0 µg/mL
Toxic Range: Greater than 15 µg/mL
 Free CarbamazepineTherapeutic Range: 1.0-3.0 µg/mL
Toxic Range: Greater than 3.8 µg/mL
 Percent Free Carbamazepine8.0-35.0%

Interpretive Data
The therapeutic range is based on serum pre-dose (trough) draw at steady-state concentration. Free carbamazepine may be important to monitor in patients with altered or unpredictable protein binding capacity. Carbamazepine is also subject to drug-drug interactions due to displacement of protein binding and extensive metabolism. Cross-reactivity with metabolites may account for differences in carbamazepine among analytical methods. Calculating percent free attempts to minimize differences in assay cross-reactivity and may be useful in dose optimization.

Note
CPT Code(s)
80156; 80157
Components
Component Test Code*Component Chart NameLOINC
2011764Carbamazepine Dose4152-5
2011765Carbamazepine Dose Frequency
2011766Carbamazepine Route
2011767Carbamazepine Type of Draw
2011768Free Carbamazepine3433-0
2011769Percent Free Carbamazepine32852-6
2011770Total Carbamazepine3432-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Atretol
  • Biston
  • Calesin
  • Carbamazepine, Free
  • Carbatrol
  • Epimaz
  • Epitol
  • Epitrol
  • Equetro
  • Finlepsin
  • Free Carbamazepine
  • Free Tegretol
  • Protein Free Carbamazepine
  • Sirtal
  • Tegretol, Free
  • Telesmin