Hepatic Cytochrome P450 Enzyme Activity Screening (via probe-based assay)
This test measures how well certain liver enzymes involved in drug metabolism work. It helps assess how your liver processes medications and toxins.
["Understanding your liver’s ability to metabolize drugs can help prevent side effects or interactions."]
Key facts at a glance
- LOINC
- 49369-2
- Short code
- HCV RNA # CSF NAA+probe
- Synonyms
- HCV RNA # CSF NAA+probe
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- CPT
- 86803
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you’re starting a new medication, have liver concerns, or are being monitored for drug interactions. Some medications rely on liver enzymes to work properly, and this test helps ensure they’re being processed safely.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the blood draw if your provider specifies. Bring a list of all medications (including over-the-counter and herbal supplements) you’re taking, as some can affect enzyme activity.
What Happens During the Test
A small blood sample is taken from a vein in your arm. The sample is analyzed using a specialized probe-based method to measure enzyme activity levels. The process is quick and typically causes only mild discomfort.
What the Results Mean
Results help determine if your liver enzymes are functioning normally or if they’re slower/faster than expected. Abnormal findings may indicate how your body processes certain drugs, which can guide dosage adjustments or avoid potential risks.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This screening is particularly useful for patients on medications that rely on liver enzymes (e.g., antidepressants, painkillers, or blood thinners). Low enzyme activity may require lower doses to prevent toxicity, while high activity might mean higher doses are needed for effectiveness. It’s also useful for monitoring liver health in chronic conditions like hepatitis or cirrhosis.
Short name
Liver enzyme activity screening
Frequently asked questions
Will I need to avoid certain foods or drinks before the test?
How long will I wait for my results?
Can this test detect liver disease?
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