Carbamazepine, Serum Concentration (Mass Concentration)
This test measures the amount of carbamazepine, a medication used to control certain types of seizures, in your blood.
["Knowing your carbamazepine levels helps doctors monitor your dose for safety and effectiveness."]
Key facts at a glance
- LOINC
- 41472-2
- Short code
- CARB-DBS
- Synonyms
- carBAMazepine DBS-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Dried Blood Spot (DBS) collection card (Whatman 903 or equivalent) with capillary blood applied to designated circles
- Units
- N/A
- Ref low
- 4
- Ref high
- 12
- Critical range
- — – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–99 years
- Method
- Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) or Immunoassay
- CPT
- 80157
- SNOMED
- 395092000
- Specimen volume
- 75-100 microliters whole blood per spot (minimum 3 spots required)
- Stability
- DBS cards stable at room temperature for 14 days, refrigerated (2-8°C) for 30 days, frozen (-20°C) for 6 months. Avoid exposure to humidity and direct sunlight.
- Hemolysis max
- 250
- Lipemia max
- 100
- Icterus max
- 25
- TAT
- 24–72 hours
- Order
- routine
Why This Test Matters
Carbamazepine is prescribed to manage epilepsy or nerve pain. Your doctor may order this test to ensure your dose is appropriate. Too little may not control symptoms, while too much can cause serious side effects. Regular monitoring helps balance these risks.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or vein to draw blood. It usually takes a few minutes. If you’re on blood thinners, let your doctor know before the test.
What the Results Mean
Results are compared to a general reference range, but exact values can vary by lab. Your doctor will interpret the results in the context of your medical history and symptoms. Abnormally high or low levels may require dose adjustments.
Common Reasons for This Test
Your doctor may order this test if you’re taking carbamazepine to treat seizures or nerve pain. It’s often done during treatment to check for effective dosing or side effects.
Reference range
Therapeutic range: 4.0-12.0 mcg/mL (trough). Levels may vary based on indication (epilepsy vs. trigeminal neuralgia) and individual patient factors.N/A
No fasting required. Trough levels should be drawn immediately before the next scheduled dose, typically in the morning. Document time of last dose and time of specimen collection. Steady-state sampling recommended (typically after 2-4 weeks of stable dosing).
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Carbamazepine Level
Frequently asked questions
Will this test affect my medication?
How often should I get this test?
Can I drink water before 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 10, 2026. · Read our editorial policy