Clarithromycin Concentration in Serum (Quantitative)
This test measures the amount of the antibiotic clarithromycin in your blood serum. Clarithromycin is used to treat bacterial infections.
["Knowing your clarithromycin levels helps your doctor monitor your treatment and ensure it’s working properly."]
Key facts at a glance
- LOINC
- 43987-7
- Short code
- Clarithro Islt Slgr Mcbct AB 12.0
- Synonyms
- Clarithro Islt Slgr Mcbct AB 12.0
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 200
- Ref high
- 900
- 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 clarithromycin to treat or manage certain infections, such as bacterial pneumonia, ear infections, or skin infections. It helps assess whether the medication is at an effective concentration in your blood.
What to Expect Before the Test
No special preparation is needed for this test. You may have a small needle inserted into your arm to draw blood, similar to a routine blood draw. The process is quick and usually painless.
What the Test Results Mean
Results are typically reported in micrograms per milliliter (mcg/mL). They help determine if your dose is appropriate for your infection and whether you’re responding to treatment. Your doctor will interpret these results in the context of your medical history and symptoms.
Common Uses and Considerations
Clarithromycin is a macrolide antibiotic, often used when other antibiotics are not suitable. Overuse or incorrect dosing can lead to antibiotic resistance, so monitoring levels is important in some cases.
Reference range
NCBI: Vitamin B12 200-900 pg/mLN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clarithromycin levels may be checked if you have kidney or liver problems, are taking other medications that interact with clarithromycin, or if you’re experiencing side effects like nausea, diarrhea, or rash.
Short name
Clarithromycin Level
Frequently asked questions
Why might my doctor request this test more than once?
What happens if my clarithromycin level is too low or too high?
Can I eat or drink before this test?
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 17, 2026. · Read our editorial policy