Home
HelpTest Code LAB303 Carbamazepine (Tegretol), Total, Plasma or Serum
Additional Codes
| Test Name in EPIC | EPIC Test Code | Mnemonic |
|---|---|---|
| CARBAMAZEPINE | LAB0303 | TEG |
Test Alias
Tegretol; Carbam; Teg
Useful For/Utility
The measurements obtained are used in monitoring levels of carbamazepine to help ensure appropriate therapy.
Methodology
Enzyme Immunoassay
Clinical Information
Carbamazepine (Tegretol) is used in the control of partial seizures with both temporal lobe and psychomotor symptoms, and 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 5-8 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.
Specimen Requirements
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Plasma
Container/Tube: Light-green top (lithium heparin gel)
Specimen Volume: 1 mL
Specimen Minimum Volume: 0.5 mL
Collection Instructions:
1. Draw trough specimen 30 minutes prior to next oral dose. When toxicity is suspected, draw level when ordered STAT.
2. Spin down and separate within 2 hours of draw.
Additional Information:
1. Avoid repeated freeze/thaw cycles.
2. Label specimen appropriately (plasma).
Alternate:
Specimen Type: Serum
Container/Tube: Red top or serum gel
Specimen Volume: 1 mL
Specimen Minimum Volume: 0.5 mL
Collection Instructions:
1. Draw trough specimen 30 minutes prior to next oral dose. When toxicity is suspected, draw level when ordered STAT.
2. Spin down and separate within 2 hours of draw.
Additional Information:
1. Avoid repeated freeze/thaw cycles.
2. Label specimen appropriately (serum).
Specimen Transport Temperature
Refrigerate 5 days/Ambient 24 hours OK/Frozen OK
Day(s) Test Set Up
Monday through Sunday
Performing Laboratory
Chemistry -
St. Joseph's Medical Center Lab; Fargo Hospital Lab; Northern Pines Lab; Sandstone Hospital Lab; SMDC Clinical Lab; St. Mary's - Detroit Lakes Hospital Lab; St. Mary's Hospital - Superior Lab; Moose Lake Hospital Lab
Test Classification and CPT Coding
80156
Reference Values
Therapeutic concentration: 4.0-12.0 µg/mL