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Serum/plasma concentration of carbamazepine (mass concentration)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of carbamazepine, a medication used to treat certain types of seizures or nerve pain, in your blood.

Quick summary

["Knowing your carbamazepine levels helps doctors monitor your dose and ensure it’s working safely for your condition."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
54055-9
Short code
HEDIS 2009 MPM-E carBAMazepine
Synonyms
HEDIS 2009 MPM-E carBAMazepine
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
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
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you’re taking carbamazepine to check if your dose is appropriate. It helps prevent side effects like dizziness, drowsiness, or low blood counts while ensuring the drug is working properly.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein (usually in your arm) to draw blood. If you’re on blood thinners, let your doctor know before the test.

What the Results Mean

Results are used to adjust your medication if needed. Too little carbamazepine may mean your seizures or pain aren’t controlled, while too much could increase risks like dizziness or rash.

Common Side Effects to Watch For

While rare, high levels may cause nausea, fatigue, or coordination problems. If you experience these or other unusual symptoms, contact your doctor.

Reference range

Therapeutic: 4-12 mcg/mLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Carbamazepine levels help prevent over- or under-treatment, balancing safety and effectiveness for long-term seizure or pain management.

Short name

Carbamazepine Level

Frequently asked questions

Why might my doctor want to check my carbamazepine levels regularly?
Your doctor may monitor levels to adjust your dose, especially if you’re taking other medications that could affect carbamazepine’s effectiveness or safety.
What happens if my carbamazepine level is too high or too low?
Too high could mean side effects like dizziness or rash, while too low might mean your seizures or pain aren’t controlled. Your doctor will guide you on what to do next.
Can I eat or drink before this test?
You can eat and drink normally unless your doctor says otherwise. Avoid caffeine or alcohol before the blood draw if instructed.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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