Ethambutol Concentration in Serum or Plasma
This test measures the amount of the drug ethambutol in your blood. Ethambutol is used to treat tuberculosis and may be prescribed alongside other medications.
["Your doctor may check this level to ensure the drug is working properly and to avoid potential side effects."]
Key facts at a glance
- LOINC
- 25187-6
- Short code
- Ethambutol Islt Slgr Mcbct AB 7.5
- Synonyms
- Ethambutol Islt Slgr Mcbct AB 7.5
- 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 healthcare provider may order this test if you’re taking ethambutol to treat tuberculosis. They may also request it to monitor your response to the medication or check for toxicity, especially if you have kidney issues or are taking other medications that interact with ethambutol.
What to Expect Before the Test
No special preparation is needed for this test. You may have a small needle inserted into your arm or vein to draw blood. If you’re using an at-home test kit, follow the instructions provided with the kit.
What the Test Results Mean
Ethambutol levels can vary based on how your body processes the drug, your dose, and other health factors. Your results will be compared to a reference range specific to your treatment plan and medical history. Low levels may indicate insufficient medication, while high levels could signal toxicity.
Possible Side Effects and Risks
Ethambutol can cause side effects like vision changes (such as blurred or reduced color vision), which is why monitoring its levels is important. Rarely, it may affect your kidneys or cause allergic reactions. Always report any unusual symptoms to your doctor.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Ethambutol is a key antibiotic in tuberculosis treatment. Maintaining appropriate blood levels helps ensure the drug is effective while minimizing risks. Low levels may mean the infection isn’t fully controlled, while dangerously high levels could harm your kidneys or eyes. Regular monitoring helps balance effectiveness and safety.
Short name
Ethambutol Level
Frequently asked questions
What does a normal ethambutol level mean for my health?
Can I eat or drink before this test?
How long will it take to get my test results?
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 16, 2026. · Read our editorial policy