Test Code CARBA Carbamazepine
Additional Codes
Epic: LAB21
Specimen Required
Specimen Type: Serum
Collection Container/Type: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 3mL
Collection Instructions:
- In a patient on regular medication regimen, the sample should be drawn immediately prior to next carbamazepine dose.
-
Centrifuge and separate cells after clot formation and within 4 hours of collection.
Specimen Minimum Volume
0.3 mL
Specimen Stability
Room temperature: 24 hours
Refrigerated: 7 days
Frozen: 14 days
Reference Range
4.00 - 12.00 µg/mL
Rejection Due To
Unlabeled, mislabeled, wrong tube type, hemolyzed, QNS, exceeds specimen stability requirements.
Report Available
Same day
Clinical Significance
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.
Method Name
Chemiluminescent microparticle immunoassay (CMIA)
Limitations
For diagnostic purposes, results should be used in conjunction
with other data: symptoms, results of other tests, clinical
impressions, etc.
Potentially interfering substances include : Hemoglobin
>500 mg/dL; Bilirubin >20 mg/dL; Triglycerides
>3000 mg/dL; Total Protein >12 g/dL
Patients receiving mouse monoclonal antibodies for diagnosis or
treatment may develop Human anti-mouse antibodies (HAMA).
HAMA may cause falsely elevated or decreased values when
tested with assay kits which employ mouse monoclonal antibodies.
Additional information may be required for diagnosis.
Heterophilic antibodies in human serum can react with reagent
immunoglobulins, interfering with in vitro immunoassays.
Aliases
Tegretol
LOINC
3432-2
Day(s) Performed
Daily