Carbamazepine Concentration (Serum/Plasma)
This test measures the amount of carbamazepine, a medication used to treat certain types of seizures and nerve pain, in your blood.
["Your doctor may check this level to ensure the drug is working properly and to avoid harmful side effects."]
Key facts at a glance
- LOINC
- 35237-7
- Short code
- CARB
- Synonyms
- carBAMazepine SerPl-msCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum tube (no anticoagulant) or serum separator tube (SST/gold-top)
- Units
- N/A
- Ref low
- 4
- Ref high
- 12
- Critical range
- — – 15 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (e.g., chemiluminescent immunoassay, fluorescence polarization immunoassay) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 80156
- SNOMED
- 1026991000119102
- Specimen volume
- 1.0–2.0 mL of serum
- Stability
- Room temperature: 8 hours. Refrigerated (2–8°C): 48 hours. Frozen (-20°C or below): 4 weeks. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 30
- TAT
- 1–4 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you’re taking carbamazepine to manage conditions like epilepsy, bipolar disorder, or trigeminal neuralgia. It helps monitor your dose to balance effectiveness and safety.
What Does the Test Involve?
A blood sample is taken from a vein in your arm. The sample is sent to a lab where it’s analyzed to measure carbamazepine levels using a specialized test method.
What Does the Result Mean?
Results aren’t provided with specific reference ranges here, as they depend on your individual needs and the dose prescribed. Your doctor will interpret the result in relation to your treatment plan.
What Are Possible Side Effects?
Carbamazepine can cause side effects like dizziness, drowsiness, or gastrointestinal upset. Rarely, it may affect blood cells or cause serious allergic reactions. Always report unusual symptoms to your doctor.
Reference range
Therapeutic range: 4.0–12.0 mcg/mL (or mg/L). Optimal target levels may vary based on clinical indication, patient response, and concomitant medications.N/A
No fasting required. Trough levels should be drawn immediately before the next scheduled dose (typically in the morning). Document the time of last dose and sample collection time on the requisition.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Carbamazepine Level
Frequently asked questions
What If My Level Is Too High?
What If My Level Is Too Low?
How Often Should I Get This Test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy