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Sulfisoxazole in Urine (24-Hour Collection)

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

This test measures the amount of sulfisoxazole, a sulfonamide antibiotic, in your urine over a 24-hour period. It helps assess how well your body is processing this medication.

Quick summary

["This test helps monitor antibiotic levels in your urine to ensure proper dosing and avoid excess exposure."]

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

Key facts at a glance

LOINC
73137-2
Short code
Sulfisoxaz ind plt IgG SerPl Ql FC
Synonyms
Sulfisoxaz ind plt IgG SerPl Ql FC
Category
hematology
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
CPT
82784
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 sulfisoxazole (a medication used to treat certain bacterial infections) and want to check how your body is handling it. It’s also used in research or specialized clinical settings to study antibiotic metabolism.

What to Expect Before the Test

You’ll need to collect all urine for a full 24-hour period, typically starting after waking up the first morning. Store the urine in a refrigerator and return it to the lab on time. Follow your provider’s instructions precisely to ensure accurate results.

How the Test Works

The collected urine is analyzed to measure sulfisoxazole levels. This involves a specialized laboratory technique to detect and quantify the antibiotic in your urine.

What the Results Mean

Results may indicate whether your dose is too high or too low, helping your provider adjust treatment. However, specific reference ranges vary by lab and clinical context.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Sulfisoxazole urine levels are critical for managing antibiotic therapy, especially in cases where dosing adjustments are needed. Abnormal results may signal improper absorption, metabolism issues, or potential toxicity.

Short name

Sulfisoxazole Urine

Frequently asked questions

What causes sulfisoxazole to appear in urine?
Sulfisoxazole is naturally excreted in urine after your body processes it. If you’re taking the medication, your urine will contain measurable levels. In rare cases, false positives may occur due to contamination or unrelated medications.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing times. Your provider will contact you once they’re ready.
Can I drink alcohol before this test?
Alcohol use may not directly affect sulfisoxazole levels in urine, but it can impact your overall health and medication response. Follow your provider’s advice on lifestyle adjustments before testing.
  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