16th May 2025

Tacrolimus

Tacrolimus is a highly potent immunosuppressant that works via the inhibition of calcineurin which reduces the production of cytokine genes for proteins such as interleukin-2, tumour necrosis factor-alpha and interferon gamma, ultimately reducing the proliferation of T-lymphocytes.

Before initiating tacrolimus therapy, a number of baseline investigations should be performed including:

• Blood pressure
• Blood tests – full blood count, urea & electrolytes, renal function, liver function, clotting screening, plasma proteins
• Fasting blood glucose
• ECG – to look for hypertrophic changes
• Hepatitis and HIV screening if patients are at risk of infection

Once therapy has begun, whole blood trough tacrolimus levels should be taken twice each week and once stable, they should be monitored if there are changes to dose, interacting medications are prescribed, or in the event of unexplained graft dysfunction. In the early post-transplant period trough levels are usually between 5-20 nanograms/mL for liver transplant recipients and 10-20 nanograms/mL for kidney and heart transplant patients. For maintenance therapy levels are usually between 5-15 nanograms/mL for liver, kidney, and heart transplant recipients. In the case of patients with severe hepatic dysfunction levels should be monitored closely due to reduced clearance and therefore prolonged half-life of the drug.

Alongside monitoring whole drug levels, the following should be monitored routinely at clinic visits:

• Blood pressure
• Blood tests – full blood count, urea & electrolytes, renal function, liver function, clotting screening, plasma proteins
• Fasting blood glucose
• Visual acuity
• Skin examination – twice a week for the first 5 years, then annually
• Lipids & Hepatitis surface antibodies annually