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Antibiotic Detection in Urine (Cefuroxime)

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

This test checks for the presence of the antibiotic cefuroxime in your urine, often used to monitor treatment for infections like urinary tract infections.

Quick summary

["Determines if your body is responding to cefuroxime therapy by detecting its presence in urine."]

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

Key facts at a glance

LOINC
101503-1
Short code
CFRX MIC
Synonyms
Cefuroxime Bld Pos MIC.VOC det
Category
chemistry
Sample
whole-blood
Container
Positive blood culture bottle (aerobic and/or anaerobic) collected into approved blood culture bottles (e.g., BACTEC, BacT/ALERT)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
mic-voc-detection
CPT
87186
SNOMED
313311003
Specimen volume
8-10 mL of blood per bottle for adults; 1-5 mL for pediatric bottles per manufacturer recommendations
Stability
Blood culture bottles should be incubated within 2 hours of collection; once positive, identification and susceptibility testing should be initiated promptly and ideally completed within 8 hours
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
8–24 hours
Order
routine

Why This Test Is Done

Your healthcare provider may order this test if you’re taking cefuroxime to treat an infection, such as a urinary tract infection (UTI). It helps ensure the medication is working and confirms whether the infection is being cleared from your system.

What to Expect Before the Test

No special preparation is needed. You’ll likely provide a urine sample in a clean container. If you’re on a specific diet or medication, let your provider know to avoid false results.

How the Test Works

The test detects cefuroxime using a sensitive method (likely immunoassay or similar) to measure its concentration in your urine. A positive result means the antibiotic is present, while a negative result suggests it’s cleared from your system.

Possible Results and Their Meaning

A positive result indicates cefuroxime is still in your urine, which may mean the infection isn’t fully resolved or the dose needs adjustment. A negative result suggests the antibiotic is working effectively.

Reference range

Interpretive criteria per CLSI M100 guidelines: Susceptible (S), Intermediate (I), Susceptible-Dose Dependent (SDD), or Resistant (R). Cefuroxime parenteral S <= 8 mcg/mL, R >= 32 mcg/mL; Cefuroxime oral S <= 4 mcg/mL, R >= 32 mcg/mLN/A

Specimen: whole-blood

No special patient preparation required. Specimen must be collected prior to next scheduled dose of antibiotic when clinically feasible to avoid false-susceptible results. Blood cultures should be drawn before initiating antimicrobial therapy whenever possible

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test plays a key role in antibiotic stewardship by confirming whether cefuroxime is being eliminated from your body. Persistent positive results may prompt adjustments to your treatment plan, such as dosage changes or switching medications, to avoid antibiotic resistance.

Short name

Cefuroxime in Urine

Frequently asked questions

What does a positive result mean?
A positive result means cefuroxime is still detectable in your urine, which could indicate the infection isn’t fully cleared or that your body isn’t processing the medication as expected. Your provider may recommend further evaluation or adjust your treatment plan.
Can diet or medications affect this test?
Yes, certain foods, supplements, or other medications (especially those affecting kidney function) could influence urine composition or antibiotic detection. Always inform your provider about all medications or dietary changes.
How soon will I get my results?
Results are typically available within 1–3 business days, depending on lab processing times. Your provider will discuss them with you during your follow-up visit.
  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