Carbamazepine concentration in serum/plasma
This test measures the amount of carbamazepine, a medication used to treat certain types of seizures and nerve pain, in your blood.
["Helps monitor your dose to ensure it’s effective and safe."]
Key facts at a glance
- LOINC
- 12363-8
- Short code
- CARBU
- Synonyms
- carBAMazepine Ur Ql
- Category
- chemistry
- Sample
- urine
- Container
- Sterile, preservative-free urine collection container
- Units
- N/A
- Ref low
- 4
- Ref high
- 12
- Critical range
- — – 15 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Immunoassay (e.g., EMIT, FPIA) or Gas Chromatography-Mass Spectrometry (GC-MS) confirmation
- CPT
- 80157
- SNOMED
- 395178002
- Specimen volume
- 30-50 mL random urine
- Stability
- Ambient: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Carbamazepine is a prescription drug that works by stabilizing electrical activity in the brain. Your doctor may order this test to check if your dose is working properly or if you’re experiencing side effects. Too much or too little can affect how well the medication controls your symptoms.
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 a blood sample. The process usually takes a few minutes. If you’re on this medication, your doctor may recommend testing at specific times (e.g., before or after doses) to track levels accurately.
What the Results Mean
Results help your healthcare provider adjust your dose if needed. They won’t provide a direct range, but they’ll compare your level to what’s typical for your condition and treatment goals. Low levels might mean the drug isn’t working well, while high levels could signal side effects or toxicity.
Common Reasons for Testing
Doctors may order this test if you’re newly prescribed carbamazepine, experiencing seizures or nerve pain, or if you’re having unusual symptoms like dizziness, drowsiness, or rash. It’s also used to monitor long-term treatment to avoid complications.
Reference range
Therapeutic: 4-12 mcg/mLN/A
No special preparation required. Patient should be informed that this is a urine drug screen. Collect specimen prior to next scheduled dose if monitoring compliance.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Carbamazepine Level
Frequently asked questions
How often should I get this test?
What if my results are out of the expected range?
Can I eat or drink before the 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 17, 2026. · Read our editorial policy