24-Hour Urine Mephenytoin Excretion Rate
This test measures how much of a medication called mephenytoin your body eliminates in urine over 24 hours. It helps assess liver function and how well your body processes certain drugs.
["This test helps doctors check liver function and drug metabolism."]
Key facts at a glance
- LOINC
- 3810-9
- Short code
- Me-phenidate 24h Ur-mRate
- Synonyms
- Me-phenidate 24h Ur-mRate
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 20
- Ref high
- 400
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82670
- 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
Why Is This Test Done?
Your doctor may order this test if they suspect liver problems or if you’re taking medications that require liver metabolism. It can also help monitor how your body handles specific drugs, such as antiepileptic medications.
What Does the Test Involve?
You’ll collect all your urine for a full 24-hour period in a special container. The sample is then sent to a lab for analysis to determine the amount of mephenytoin excreted.
Sample Collection Process
To prepare, empty your bladder at the start of the 24-hour period (e.g., midnight). Collect every urine output—including first-morning urine—into the container. Replace the lid and refrigerate if needed. Finish at the same time the next day.
What to Expect During Testing
No special preparation is needed beyond collecting urine as directed. You may experience mild discomfort if you’re taking mephenytoin, but side effects are usually temporary.
Reference range
Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: This test is primarily used to evaluate liver function and drug metabolism. Abnormal results may indicate liver impairment, poor drug clearance, or other metabolic issues. It’s less common but can be critical in specific cases, such as monitoring patients on certain antiepileptic drugs.
Short name
24h Urine Mephenytoin Rate
Frequently asked questions
What causes mephenytoin to be tested?
How long does it take to get results?
Can I drink alcohol 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 16, 2026. · Read our editorial policy