Tacrolimus/Prograf (FK506)
Private Tacrolimus/Prograf testing in London for £181, measuring one therapeutic drug level with results expected in around 1–2 days.
Turnaround time
1-2 business days
Biomarkers count
1
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Overview of the Tacrolimus/Prograf (FK506) Test
The Tacrolimus/Prograf blood test measures the concentration of Tacrolimus in whole blood, supporting therapeutic drug monitoring for people prescribed this potent immunosuppressive medicine.
The test assesses 1 specialist therapeutic drug marker: FK506 (Tacrolimus/Prograf).
Tacrolimus, also known by the historical laboratory designation FK506 and the brand name Prograf, is a calcineurin inhibitor.
It suppresses T-cell activation and is widely used to prevent rejection after organ transplantation.
Tacrolimus is also used in selected autoimmune and specialist clinical settings.
The medicine has a narrow therapeutic index.
Too little Tacrolimus can result in inadequate immunosuppression and potentially increase the risk of transplant rejection.
Too much can increase the risk of toxicity.
Potential adverse effects include kidney injury, neurological effects, electrolyte abnormalities, hypertension and changes in glucose metabolism.
The amount of Tacrolimus absorbed and metabolised varies substantially between individuals.
Interactions with other medicines can also change Tacrolimus concentrations significantly.
For these reasons, blood-level monitoring is an established part of Tacrolimus treatment.
The most commonly used measurement is a trough level, where blood is collected immediately before the next scheduled dose.
Accurate information about the dose and blood-collection time is therefore essential.
Tacrolimus levels are usually interpreted alongside kidney function, electrolytes, liver function, clinical condition and the transplant or treatment protocol.
The therapeutic target differs depending on organ transplanted, time since transplantation and other immunosuppressive treatment.
What Does the Tacrolimus/Prograf (FK506) Test Check?
The test measures Tacrolimus concentration in whole blood to support therapeutic drug monitoring and dose optimisation. This test measures 1 specialist biomarker.
FK506 (Tacrolimus/Prograf)
Measures whole-blood Tacrolimus concentration, supporting safe immunosuppressive dosing and monitoring for inadequate exposure or drug accumulation.
Who May Benefit From the Tacrolimus/Prograf (FK506) Test?
Tacrolimus monitoring is relevant to people who are currently prescribed the medicine under specialist supervision.
People who have received an organ transplant - Tacrolimus monitoring helps maintain appropriate immunosuppression while limiting toxicity.
People whose Tacrolimus dose has recently changed - Repeat measurement can determine whether the new regimen produces the intended exposure.
People starting or stopping medicines that interact with Tacrolimus - Drug interactions can cause major changes in Tacrolimus concentration.
People with changing kidney function - Tacrolimus can affect renal function and kidney impairment can complicate treatment.
People with a previous high Tacrolimus level - Repeat testing can help determine whether the concentration has returned to the intended range.
People with an unexpectedly low Tacrolimus level - Low concentrations can raise concern about absorption, adherence or drug interactions.
People with symptoms potentially compatible with Tacrolimus toxicity - Blood-level assessment can contribute to specialist review.
People undergoing routine transplant follow-up - Regular therapeutic drug monitoring forms part of many transplant protocols.
How to Prepare
The sample should be sent to the laboratory on the same day according to the specialist assay requirements.
Do not take an early or delayed Tacrolimus dose simply to alter the measured concentration.
Symptoms and Reasons to Consider the Tacrolimus/Prograf (FK506) Test
Tacrolimus levels are generally measured according to a treatment protocol rather than because of symptoms alone.
A scheduled transplant-monitoring blood test - Regular trough measurements help guide immunosuppressive treatment.
A change in kidney function - Tacrolimus exposure and renal function are closely monitored together.
New tremor or neurological symptoms - Tacrolimus can cause neurological adverse effects, particularly at excessive exposure.
Unexpected changes in potassium or Magnesium - Tacrolimus can affect electrolyte balance.
A recent dose adjustment - Repeat measurement can establish whether the new dose produces the intended blood concentration.
Starting an interacting medicine - Some antibiotics, antifungals and other medicines can substantially change Tacrolimus metabolism.
Vomiting, diarrhoea or altered absorption - Significant gastrointestinal illness can affect Tacrolimus exposure.
Concern about transplant rejection or insufficient immunosuppression - Drug level is one component of the specialist assessment.
Tacrolimus treatment must be supervised by the prescribing transplant or specialist clinical team.
Do not alter, delay or omit a Tacrolimus dose because of a laboratory result without specific medical instructions.
Significant transplant-related symptoms or suspected Tacrolimus toxicity require prompt specialist assessment.
How to Book Your Tacrolimus/Prograf (FK506) Test
The Tacrolimus/Prograf test can be booked privately for clinician-directed therapeutic drug monitoring.
Choose the Tacrolimus/Prograf (FK506)
Select the individual Tacrolimus therapeutic drug assay online.
Select your sample collection option
Choose an in-clinic blood draw or professional home or hotel phlebotomy that can meet the required dose timing and same-day laboratory transport.
Attend your appointment
A trained healthcare professional collects the required EDTA whole-blood sample at the prescribed interval from your dose.
Laboratory analysis
Your sample undergoes specialist measurement of FK506 (Tacrolimus/Prograf).
Receive your results securely
Your authorised result is delivered securely and should be reviewed by the clinician responsible for your immunosuppressive treatment.
When Will I Receive My Results?
The specialist laboratory turnaround for Tacrolimus/Prograf is approximately 1–2 days after laboratory receipt.
Tacrolimus requires dedicated therapeutic drug analysis.
The sample must be sent to the laboratory on the same day according to current specialist laboratory instructions.
The specimen undergoes quantitative measurement, quality-control procedures and result authorisation before release.
Understanding Your Results
Tacrolimus results are interpreted according to the treatment protocol rather than using one universal therapeutic range.
The target concentration depends on factors including the transplanted organ, time since transplantation, other immunosuppressive medicines and individual clinical risk.
A higher-than-intended result can indicate excessive exposure and may increase the likelihood of toxicity.
Kidney dysfunction, interacting medicines or altered metabolism can contribute.
A lower-than-intended result can indicate inadequate exposure, although sample timing must be checked before drawing conclusions.
Taking the blood sample too early or too late relative to the dose can make the result misleading.
For trough monitoring, the concentration is generally interpreted only when the specimen was collected immediately before the next planned dose.
The transplant or prescribing team should make any dose adjustment.
Why Book With London Blood Tests?
London Blood Tests provides private Tacrolimus monitoring for people requiring clinician-directed therapeutic drug measurement.
Measures Tacrolimus concentration directly - The test provides quantitative information about current drug exposure.
Supports transplant monitoring - Tacrolimus levels are routinely followed after many solid-organ transplants.
Helps reduce toxicity risk - Excessive concentrations can increase the risk of kidney and neurological adverse effects.
Supports dose optimisation - Low and high levels can guide specialist dose review.
Appropriate timed sampling - Trough collection can be coordinated with the patient's medication schedule.
Specialist laboratory analysis - Samples undergo dedicated therapeutic drug measurement.
Professional blood collection - Clinic and suitable mobile collection can be arranged where same-day transport requirements can be met.
Clear pricing - The Tacrolimus/Prograf test costs £181.
Private Tacrolimus/Prograf (FK506) Blood Test in London
London Blood Tests provides private Tacrolimus/Prograf testing for people requiring therapeutic drug monitoring under specialist supervision.
The test costs £181 and assesses 1 specialist drug marker.
Results are expected approximately 1–2 days after laboratory receipt.
Accurate dose timing, sample timing and same-day specimen transport are particularly important for reliable interpretation.