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Orotidine/Creatinine Ratio, Urine

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

A urine test that measures orotidine relative to creatinine to help evaluate possible abnormalities in pyrimidine metabolism.

Quick summary

["This test can help identify possible problems with pyrimidine metabolism, but results must be interpreted with other clinical and laboratory findings."]

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

Key facts at a glance

LOINC
17870-7
Short code
Orotidine/Creat Ur-sRto
Synonyms
Orotidine/Creat Ur-sRto
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures orotidine, a compound related to pyrimidine metabolism, in urine and compares it with the amount of creatinine in the same sample. The ratio helps account for differences in how concentrated the urine is.

Why might I need this test?

It may be ordered when a healthcare professional is evaluating suspected inherited or acquired disorders of pyrimidine metabolism. It can also be used alongside other tests when investigating unexplained metabolic or liver-related findings.

How is the test performed?

A urine specimen is collected and tested in a laboratory to determine the amounts of orotidine and creatinine. The laboratory then calculates the orotidine-to-creatinine ratio.

How do I prepare for the test?

Follow the collection instructions provided by your healthcare professional; a first-morning or random clean-catch urine sample may be requested. Fasting is generally not required, but tell your clinician about medications, vitamin supplements, and recent illness.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine orotidine/creatinine ratio

Frequently asked questions

Does this test require a blood draw?
No. It is performed using a urine sample collected according to your healthcare professional's instructions.
Why is the result reported as a ratio?
Comparing orotidine with creatinine helps reduce the effect of variations in urine concentration. Very dilute urine or impaired kidney function can still affect the ratio.
What if my result is abnormal?
Your healthcare professional will interpret the result with your symptoms, medical history, medications, and other laboratory tests. Additional testing may be needed to clarify the cause.
  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