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Lamotrigine Metabolite in Serum/Plasma (Mass Concentration)

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

This test measures the concentration of a drug metabolite in your blood. Lamotrigine is used to treat certain seizure disorders and mood disorders, and its active metabolite helps maintain therapeutic levels.

Quick summary

["Your doctor may check this test to ensure proper drug levels and side effect management."]

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

Key facts at a glance

LOINC
17259-3
Short code
Deprecated LA Methadone Metab SerPl-mCnc
Synonyms
Deprecated LA Methadone Metab 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 Is This Test Done?

Your healthcare provider may order this test if you’re taking lamotrigine (Lamictal) to monitor your treatment. It helps ensure the right amount of the drug is in your bloodstream, supporting effective seizure or mood control while minimizing risks.

What Does This Test Measure?

The test detects lamotrigine’s primary metabolite, which is formed when your body processes the medication. This metabolite contributes to how well the drug works and how your body handles it over time.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or vein to draw blood. If you’re on blood thinners, let your provider know before testing.

What to Expect After the Test

You may feel slight bruising or discomfort at the injection site, which usually fades quickly. Avoid heavy lifting or strenuous activity for a few hours afterward.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Lamotrigine Methyl (Serum/Plasma)

Frequently asked questions

Why might my doctor want to check this test?
Your doctor may order this test if you’re starting lamotrigine, adjusting your dose, or experiencing symptoms like rash, dizziness, or unusual tiredness. It helps balance the drug’s benefits with safety.
How often will I need this test?
Frequency depends on your treatment plan. Some patients need monitoring weekly or monthly, while others may only need it periodically. Follow your provider’s instructions.
What if my results are different from what I expected?
If your results are outside expected ranges, your doctor will review them with you. They may adjust your dose, check for medication interactions, or investigate other health factors affecting your levels.
  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