Rifampin Drug Concentration (Serum)
This test measures the amount of rifampin, a medication used to treat certain bacterial infections, in your blood. It helps doctors check if the drug is working at the right level.
["Your rifampin levels help ensure the medication is effective and safe for your treatment."]
Key facts at a glance
- LOINC
- 25184-3
- Short code
- rifAMPin Islt Slgr Mcbct AB 14.0
- Synonyms
- rifAMPin Islt Slgr Mcbct AB 14.0
- 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
Doctors may order this test if you’re taking rifampin to treat conditions like tuberculosis, meningitis, or other infections caused by bacteria that are resistant to other antibiotics. It helps them monitor how your body is processing the drug and adjust your treatment plan if needed.
What to Expect Before the Test
No special preparation is needed for this blood test. You may be asked to fast for a few hours before the draw, but this depends on your doctor’s instructions. On the day of the test, avoid eating or drinking anything except water for 2–4 hours before your blood sample is taken.
What Happens During the Test
A healthcare provider will insert a small needle into a vein in your arm. You may feel a slight pinch or sting, but it usually doesn’t cause pain. Blood will be drawn into a tube, and the needle will be removed. The process takes just a few minutes.
What the Results Mean
Your rifampin level results will be compared to a reference range provided by your doctor. If the levels are too low, your medication may not be working as intended. If they’re too high, it could lead to side effects. Your doctor will discuss the results with you and adjust your treatment if necessary.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Rifampin levels are critical for managing infections like tuberculosis, where dosing must be carefully controlled. Low levels may indicate poor absorption or metabolism, requiring higher doses. High levels can cause nausea, vomiting, or other side effects, so monitoring helps balance effectiveness and safety.
Short name
Rifampin Level
Frequently asked questions
How long does it take to get my rifampin test results?
Can I eat or drink anything before my rifampin blood test?
Will I experience any side effects from rifampin besides those related to the test itself?
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