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Ethionamide concentration in serum/plasma

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

This test measures the amount of ethionamide, a medication used to treat certain types of tuberculosis, in your blood.

Quick summary

["Ethionamide levels help doctors monitor your treatment effectiveness and adjust your dose if needed."]

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

Key facts at a glance

LOINC
25231-2
Short code
Ethionamide Islt Slgr Mcbct AB 10.0
Synonyms
Ethionamide Islt Slgr Mcbct AB 10.0
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
method-for-slow-growing-mycobacteria-antibiotic-concentration-at-ug-ml
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 ethionamide to treat tuberculosis or other infections caused by Mycobacterium species. It helps ensure the drug is working properly and at the right level in your bloodstream.

How the Test Works

A blood sample is taken and analyzed using a sensitive laboratory method to detect ethionamide. The test measures its concentration in your serum or plasma.

What to Expect Before the Test

No special preparation is needed, but inform your doctor about any medications you’re taking, including over-the-counter drugs or supplements, as they may affect results.

Possible Results and Interpretation

Results are compared to a reference range specific to your treatment regimen and health status. Low levels may indicate insufficient medication absorption, while very high levels could signal overdose or improper dosing.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Ethionamide levels are critical for managing tuberculosis treatment. Optimal levels ensure bacterial suppression without causing toxicity. Frequent monitoring helps prevent resistance and side effects, improving treatment outcomes.

Short name

Ethionamide Level

Frequently asked questions

When might I need this test?
You may need this test if your doctor prescribes ethionamide to treat tuberculosis or related infections. It’s often done during treatment to check how well your body is responding.
What does a low or high ethionamide level mean?
A low level may mean the medication isn’t working as intended, while a high level could indicate improper dosing or kidney issues. Your doctor will discuss results with you based on your full medical picture.
Can I eat or drink before this test?
You can eat and drink normally unless instructed otherwise by your doctor. Avoid alcohol or certain medications that could interfere with the 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