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Lamotrigine Serum/Plasma Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of lamotrigine, a medication used to treat certain types of seizures or mood disorders, in your blood.

Quick summary

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

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
6948-4
Short code
lamoTRIgine SerPl-mCnc
Synonyms
lamoTRIgine SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
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 Matters

Lamotrigine is prescribed to manage epilepsy or bipolar disorder, and its effectiveness depends on maintaining safe blood levels. Your doctor may order this test to check if your dose is appropriate or if adjustments are needed.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. The test is quick and typically done in a clinic or lab.

What the Results Mean

Results show your current lamotrigine concentration. While there’s no single ‘normal’ range (as it varies by dose and condition), your doctor will compare it to your prescribed dose to guide treatment decisions.

Common Reasons for Testing

Doctors may order this test if you’re new to lamotrigine, experiencing side effects, or having difficulty controlling seizures/mood symptoms. It helps prevent overdose or underdose risks.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Lamotrigine levels are critical because they can affect safety. Too little may mean the medication isn’t working, while too much can cause serious side effects like rash or dizziness. Regular monitoring helps balance effectiveness and safety.

Short name

Lamotrigine Level

Frequently asked questions

What causes my doctor to request this test?
Your doctor may order it to check if your dose is correct, adjust treatment, or investigate symptoms like rash, confusion, or worsening seizures.
How often should I get this test?
Frequency depends on your condition and dose. Typically, it’s done every few months or as needed to monitor safety and effectiveness.
Can I eat or drink before the test?
You can eat normally, but avoid alcohol or caffeine before the blood draw, as they might affect test results.
  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 16, 2026. · Read our editorial policy