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Clarithromycin Concentration in Serum

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

This test measures the amount of clarithromycin, an antibiotic, in your blood serum to check how your body is processing it.

Quick summary

["Helps monitor antibiotic levels for optimal dosing and safety."]

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

Key facts at a glance

LOINC
25192-6
Short code
Clarithro Islt Slgr Mcbct AB 32.0
Synonyms
Clarithro Islt Slgr Mcbct AB 32.0
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 healthcare provider may order this test if you’re taking clarithromycin (a medication like Biaxin) to ensure it’s working properly and at safe levels in your blood. This is especially important if you have kidney problems or are taking other medications that interact with clarithromycin.

How the Test Works

A blood sample is taken from a vein, usually in your arm. The sample is then analyzed using a sensitive chemical test to measure the concentration of clarithromycin in your serum.

What to Expect Before the Test

No special preparation is needed, but let your provider know if you’re on blood thinners, have allergies, or are pregnant. Avoid eating or drinking for at least 8 hours before the test if instructed.

What to Expect During the Test

You’ll lie down comfortably while a healthcare professional inserts a small needle into your vein. You may feel a slight pinch, but the process usually takes just a few minutes. The needle is removed quickly, and you can resume normal activities afterward.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Clarithromycin Level

Frequently asked questions

When might I need this test?
If you’re taking clarithromycin for a bacterial infection and your doctor wants to check if your body is processing the medication correctly, especially if you have kidney issues or take other medications that could affect it.
How long will it take to get my results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your provider will discuss them with you during your follow-up visit.
Can I eat or drink before this test?
Follow your provider’s instructions—usually, you should avoid food and liquids for 8 hours before the test to get an accurate reading.
  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