Prograf .5 mg/1 (Tacrolimus CAPSULE, GELATIN COATED) .5 mg/1

Tacrolimus is used to prevent rejection after solid organ transplantation, given in combination with other immunosuppressants.

• Prevention of kidney transplant rejection: a mainstay of maintenance immunosuppression after renal transplantation.
• Prevention of liver transplant rejection: used shortly after surgery and continued long term.
• Prevention of heart transplant rejection: given as part of a combination regimen.
• Prevention of lung transplant rejection: included in the licensed indications alongside other immunosuppressants.
• Paediatric transplantation: used in children, who often need higher weight-adjusted doses than adults.
• Fine dose titration: the 0.5mg strength allows small adjustments to hit the target blood level.

• Tacrolimus suppresses the T-lymphocytes that recognise a transplanted organ as foreign. Inside the cell it binds a protein called FKBP-12, and this complex blocks calcineurin, an enzyme the cell needs in order to switch on the genes for interleukin-2 and other activating signals. Without interleukin-2, T-cells cannot multiply or mount a full attack on the graft. The effect is on activation rather than destruction, so it reverses when treatment stops.

Kidney function, blood pressure, blood sugar, and potassium all need regular monitoring throughout treatment.

Common Side Effects

• Tremor and headache: common neurological effects, often dose-related.
• Reduced kidney function: rising creatinine is frequent and prompts dose review.
• Raised blood sugar and new-onset diabetes: common enough to require routine glucose monitoring.
• High blood potassium and high blood pressure: both frequently need treatment in their own right.

Serious or Rare Side Effects

• Serious and opportunistic infections: including BK virus nephropathy and, rarely, progressive multifocal leukoencephalopathy; report fever or persistent illness.
• Lymphoma and skin cancer: immunosuppression raises the risk of post-transplant lymphoproliferative disorder and skin malignancy; report new lumps or skin lesions.
• Neurotoxicity, QT prolongation, or thrombotic microangiopathy: seek urgent care for seizures, confusion, visual disturbance, or palpitations.

Tacrolimus has a narrow therapeutic range and carries boxed warnings, so it must be prescribed and monitored by transplant specialists.

• Prescribe only under specialist supervision: treatment requires physicians experienced in immunosuppression and facilities with full laboratory support.
• Monitor blood levels routinely: trough concentrations guide dosing, since both under-exposure and over-exposure cause serious harm.
• Take doses consistently: give the capsules the same way each time in relation to food, since food alters how much drug is absorbed.
• Avoid grapefruit entirely: grapefruit and its juice raise tacrolimus levels and the risk of toxicity.
• Protect against skin cancer: limit sun and ultraviolet exposure, use high-factor sunscreen, and wear protective clothing.
• Do not switch formulations casually: immediate-release and extended-release tacrolimus are not interchangeable and errors have caused graft rejection.

Tacrolimus is metabolised by CYP3A4 and interacts with a long list of medicines, so review the full list before any change.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (ketoconazole, voriconazole, clarithromycin, ritonavir): these sharply raise tacrolimus levels and the risk of kidney and neurological toxicity.
• Strong CYP3A4 inducers (rifampicin, carbamazepine, St John’s wort): these lower levels and can allow graft rejection.

Moderate Interactions (Monitor Closely)

• Nephrotoxic drugs (aminoglycosides, amphotericin B, NSAIDs): the combined load on the kidneys raises the risk of injury.
• Cannabidiol: raises tacrolimus concentrations, so monitor levels and consider a dose reduction.
• Potassium-sparing diuretics and potassium supplements: these add to the risk of high blood potassium.