Tacrolimus Level (Tacrolimus) Test
About Tacrolimus Level (Tacrolimus) Test
| Field | Value |
|---|---|
| Also Known As | FK-506 test, Prograf test, Tacrolimus trough test, Tac Level test, FK506 level test |
| Sample Type | Whole venous blood (EDTA tube) |
| Fasting Required | No fasting required; sample must be collected immediately before the next scheduled dose |
| Report Time | Typically 1 to 3 days after the sample is taken |
| Recommended For | All ages, male and female; organ transplant recipients and selected autoimmune disease patients |
| Price | Starting at ₹3,500 |
What Is a Tacrolimus Level (Tacrolimus) Test?
The tacrolimus test measures the concentration of tacrolimus, an immunosuppressant drug, in your blood. Doctors prescribe this test to check whether the drug is at a safe and effective level in the body.
It is also called the tacrolimus trough test or the FK-506 test. A whole blood sample collected from a vein in the arm is used for this analysis.
What Does a Tacrolimus Level (Tacrolimus) Test Measure?
Tacrolimus is a drug that suppresses the immune system. It binds extensively to red blood cells, with approximately 90% of the drug found within the cellular components of blood rather than in the liquid plasma. The test measures a single value: the tacrolimus level in whole blood, expressed in nanograms per millilitre (ng/mL).
The table below summarises what this measurement tells your doctor.
| Component Measured | Why It Matters |
|---|---|
| Tacrolimus blood concentration | Confirms the drug is within the safe, effective range |
| Trough level (pre-dose concentration) | Reflects the lowest point of drug exposure, used for consistent comparisons |
Why Is a Tacrolimus Level (Tacrolimus) Test Done?
Tacrolimus has a narrow therapeutic window between a dose that is effective and one that causes harm. This test helps doctors keep that balance. It is used both immediately after a transplant and throughout long-term therapy.
Common Symptoms That May Require This Test
Your doctor may request a tacrolimus blood test if you experience any of the following symptoms while taking tacrolimus.
- Tremors or shaking of the hands
- Persistent headache
- Nausea or stomach discomfort
- High blood pressure
- Swelling in the limbs
- Fever or signs of infection
- Symptoms suggesting the transplanted organ may not be functioning well
Conditions This Test Can Help Detect
The tacrolimus level test is used to monitor and detect the following conditions.
- Solid-organ transplant rejection (kidney, liver, or heart)
- Nephrotoxicity, meaning drug-related kidney damage
- Neurotoxicity, meaning drug-related nerve damage
- New-onset diabetes after transplantation
- Anaemia and gastrointestinal complications linked to tacrolimus therapy
- Autoimmune conditions such as severe atopic dermatitis, rheumatoid arthritis, and inflammatory bowel disease
Tacrolimus Level (Tacrolimus) Test for Chronic Disease Monitoring
Tacrolimus monitoring is a lifelong requirement for transplant recipients. The drug has a narrow therapeutic range, meaning even small changes in dose or body chemistry can push levels too high or too low. After a transplant, testing may happen several times a week, then gradually less often as levels stabilise. The test continues indefinitely to protect the transplanted organ and minimise side effects.
How to Prepare and What to Expect
Collecting the sample at exactly the right time is the single most important part of preparing for this test.
Do You Need to Fast?
No fasting is required before the tacrolimus test. However, the sample must be collected immediately before your next scheduled tacrolimus dose, typically about 12 hours after your last dose. This is known as the trough level. Do not take your medication until after the blood sample has been collected.
Practical Tips Before Your Test
The following steps will help ensure an accurate result.
- Note the exact time and amount of your last tacrolimus dose before arriving for the test
- Avoid grapefruit, pomelo, and products containing St. John's Wort, as these alter drug levels in the blood
- Inform the doctor or phlebotomist about all medications, supplements, and herbal products you currently take
- Wear loose-fitting clothing with easy access to the arm for blood collection
- Stay well hydrated, as dehydration can affect sample quality
Step-by-Step Procedure
Here is what to expect from the blood collection process.
- Arrive at the collection point (or welcome the home-visit phlebotomist) before your scheduled tacrolimus dose for the day
- Confirm the time of your last dose with the phlebotomist, so this is recorded alongside your sample
- A trained phlebotomist cleans a small area on your forearm and inserts a fine needle into a vein to draw blood
- The blood is collected into a special EDTA tube, which prevents it from clotting
- The needle is removed, a small dressing is applied, and the sample is labelled immediately
- The sealed sample is dispatched to the laboratory, where it is processed using liquid chromatography tandem mass spectrometry for precise measurement
Factors That Can Affect Accuracy
The following factors can influence your tacrolimus level result.
- Collecting the sample at the wrong time relative to your last dose
- Taking grapefruit juice or St. John's Wort
- Concurrent use of antifungal medications, certain antibiotics, or calcium channel blockers, which raise levels
- Use of anticonvulsants such as phenytoin or carbamazepine, or rifampicin, which lower levels
- Liver function changes, including those following liver surgery
- Anaemia or low albumin, which can alter the proportion of free drug in the blood
Understanding Your Tacrolimus Level (Tacrolimus) Test Results
Your result will be reported as a single number in ng/mL. The target range depends on the organ transplanted and how much time has passed since surgery. The table below shows the general therapeutic ranges used as a guide.
| Transplant Type and Stage | Therapeutic Range (ng/mL) |
|---|---|
| General reference range | 5 to 15 |
| Kidney transplant (1 to 3 months) | 6 to 9 |
| Kidney transplant (over 3 months) | 4 to 8 |
| Heart transplant (less than 3 months) | 9 to 12 |
| Heart transplant (from 3 to 6 months) | 8 to 9 |
| Heart transplant (from 6 to 12 months) | 6 to 8 |
| Heart transplant (over 12 months) | 4 to 8 |
| Liver transplant (1 to 12 months) | 5 to 20 |
These ranges are general guidelines and can vary by transplant centre. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Certain health conditions can shift tacrolimus levels independent of your dose. Patients with significant liver impairment process tacrolimus more slowly. This leads to higher whole-blood concentrations and an increased risk of kidney damage, necessitating closer monitoring.
In patients with anaemia or low blood albumin (such as some pregnant transplant recipients), a greater proportion of tacrolimus circulates in its free, active form. Applying standard trough targets without accounting for this can result in overexposure and toxicity.
How to Maintain Healthy Levels
The following general wellness habits support stable tacrolimus levels.
- Take your tacrolimus at exactly the same times each day, without skipping doses
- Avoid grapefruit, pomelo, and St. John's Wort throughout your treatment
- Attend every scheduled blood test and follow-up appointment so your doctor can adjust your dose promptly if needed
Lupin Diagnostics Tacrolimus Level (Tacrolimus) Test Price and Home Collection
The tacrolimus test cost at Lupin Diagnostics starts at ₹3,500, and home sample collection is available across major Indian cities. The table below shows approximate prices by city.
| City | Approximate Price (₹) |
|---|---|
| Mumbai | ₹3,500 |
| Chennai | ₹3,500 |
| Bangalore | ₹3,500 |
| Hyderabad | ₹3,500 |
| Kolkata | ₹3,500 |
| Bhopal | ₹3,500 |
| Pune | ₹3,500 |
| Guwahati | ₹3,500 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
- Select the test on the Lupin Diagnostics website
- Choose your city and preferred time slot
- Opt for home sample collection by a certified phlebotomist, or visit your nearest Lupin Diagnostics centre
- Receive your report via email or WhatsApp within the stipulated turnaround time
Home Collection
Home collection for the tacrolimus blood test is available across cities. A certified phlebotomist visits your home at the scheduled time, ensuring the sample is collected at the correct trough point before your dose. All samples are processed in NABL-accredited laboratories, and your digital report is delivered directly to you.
Frequently Asked Questions
The tacrolimus level test checks how much of the drug is present in your blood. It confirms the concentration is high enough to prevent the body from rejecting the transplanted organ, yet low enough to avoid harmful side effects such as kidney damage or nerve problems.
Blood must be collected immediately before your next scheduled dose of tacrolimus. This is called the trough level and is usually about 12 hours after your last dose. Always wait until after the sample is taken before swallowing your medication.
No fasting is required for the tacrolimus test. However, avoid grapefruit, pomelo, and St. John's Wort, as these substances can significantly change the amount of tacrolimus in your blood and affect your result.
In the weeks immediately after a transplant, testing may happen several times per week. Once your levels are stable, the frequency gradually reduces. However, because tacrolimus is a lifelong medication for most transplant recipients, monitoring continues indefinitely.
A level above the therapeutic range increases the risk of toxicity. This can include kidney damage, tremors, raised blood pressure, high blood sugar, and electrolyte imbalances. Your doctor will review the result and may adjust your dose accordingly.
Yes. Several common medicines interact with tacrolimus. Antifungal drugs, certain antibiotics such as erythromycin and clarithromycin, and calcium channel blockers can raise levels. Anticonvulsants and rifampicin can lower them. Always tell your doctor about every medication and supplement you take before the FK506 level test.
Home collection is available for the tacrolimus test through Lupin Diagnostics in major cities across India. You can book online, and a trained phlebotomist will visit at a time that fits your dosing schedule.
Tacrolimus Level (Tacrolimus) Test
