Tacrolimus is a potent immunosuppressant with clinical activity similar to ciclosporin. Oral tacrolimus is used to prevent organ rejection in patients following a liver, heart or kidney transplant.

It is also used in hospital to treat organ rejection that is resistant to other immunosuppressant medication.

Tacrolimus has a narrow therapeutic index and small changes in blood levels can cause either organ rejection or signs of toxicity.

Different oral formulations of tacrolimus are not considered interchangeable and consequently tacrolimus should always be prescribed by brand name.

A Drug Safety Update was issued by MHRA in November 2017 to reinforce the advice that oral tacrolimus products should be prescribed and dispensed by brand name only.

A Drug Safety Update was issued previously in June 2012 providing the same guidance. The availability or imminent launch of new oral tacrolimus products has prompted this advice to be re-issued.

Pharmacists who receive prescriptions requesting generic oral tacrolimus are advised to contact the prescriber to confirm the brand required and request that future prescriptions specify the brand required.

Where it is necessary to transfer a patient to a different brand the patient should be supervised and receive monitoring from an appropriate specialist.