Tacrolimus concentration in plasma
This test measures the amount of tacrolimus, a medication used to prevent organ rejection after a transplant, in your blood plasma.
["Tacrolimus levels help ensure your dose is safe and effective for managing transplant rejection."]
Key facts at a glance
- LOINC
- 72945-9
- Short code
- Tacrolimus (neut) IgM SerPl Ql FC
- Synonyms
- Tacrolimus (neut) IgM SerPl Ql FC
- Category
- chemistry
- 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 Is This Test Done?
Your healthcare provider may order this test to monitor your tacrolimus levels, especially if you’re taking this medication to prevent your body from rejecting a transplanted organ (e.g., heart, liver, or kidney). Proper dosing is critical to avoid side effects like high blood pressure, infections, or organ damage.
What to Expect Before the Test
No special preparation is usually needed. You may have a small needle inserted into a vein (venipuncture) in your arm. The test involves drawing a small amount of blood, which typically takes a few minutes. If you’re on a transplant regimen, your provider may schedule this test regularly.
What the Results Mean
Results help your doctor adjust your medication to keep levels within a target range. Too little tacrolimus may not prevent rejection, while too much can cause harmful side effects. Your doctor will discuss these results with you and adjust your treatment plan as needed.
Common Side Effects to Watch For
While rare, high tacrolimus levels can cause symptoms like nausea, headaches, or tremors. If you experience unusual fatigue, vision changes, or signs of infection (e.g., fever, sore throat), contact your healthcare provider immediately.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Tacrolimus levels are crucial for transplant patients because they directly impact organ survival and your overall health. Blood tests are used to balance the risk of rejection versus side effects, ensuring long-term stability.
Short name
Tacrolimus Level
Frequently asked questions
Why do I need this test regularly if I’m on tacrolimus?
What happens if my tacrolimus level is too high?
Can I eat or drink anything 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