Anti-rejection drugs

Anti-rejection drugs, used to counteract the reactions that transplantation can trigger, are different but all act as immunosuppressants.

What are they

The category of anti-rejection drugs includes all those substances that are used in transplant patients (of organs or tissues) in order to prevent the reactions that the transplant can trigger.

They are of two types: the rejection proper, or the reaction of the organism towards the organ or tissue of the donor, and its mirror form, called “graft versus host disease” (GVHD), which represents one of the most frequent and fearsome complications of bone marrow transplantation.

How they work

The drugs used to combat rejection and GVHD all act as modulators of immune mechanisms and, in particular, as immunosuppressants.

In fact, both transplant rejection and GVHD are due to an immune reaction: of the recipient’s immune system towards transplantation the first and of the immune cells present in the transplanted organ or tissue towards the recipient’s tissues the second

The main target of anti-rejection drugs are T lymphocytes, whose proliferation and activation they prevent.

What are they?

According to their mechanism of action, anti-rejection drugs are divided into the following classes:

Anti-rejection drugs Active ingredients
Calcineurin inhibitors Cyclosporine, tacrolimus
mTOR protein inhibitors Sirolimus, everolimus
Antiproliferative Azathioprine, mycophenolate mofetil
Corticosteroids Prednisolone, hydrocortisone
Anti-interleukin 2 monoclonal antibodies Basiliximab, daclizumab
Polyclonal anti-thymocyte antibodies ATG
Polyclonal anti-T lymphocyte antibodies ALG


Anti-rejection therapy has the dual purpose of preventing the onset of the unwanted immune reaction (prophylaxis) and of counteracting it when it is in progress (treatment).

In general, patients who have undergone a solid organ transplant (kidney, heart, lung, liver, pancreas, etc.) are treated with a corticosteroid combined with a calcineurin inhibitor (cyclosporine or tacrolimus) or an antiproliferative (azathioprine or mycophenolate mofetil) or with all three types of drugs (triple therapy).

mTOR inhibitors and monoclonal antibodies are used in particular for the prophylaxis of rejection in kidney transplantation.

For the prophylaxis and treatment of GVHD, mainly monoclonal and polyclonal antibodies, cyclosporine, corticosteroids, tacrolimus, sirolimus are used.


Anti-rejection drugs have different side effects depending on the type of molecule and the mechanism of action.

What unites them all, precisely because of their effectiveness as immunosuppressants, is the increased risk of infections (viral, bacterial, fungal), due to the inhibition of the immune defenses.

Joycelyn Elders is the author and creator of EmpowerEssence, a health and wellness blog. Elders is a respected public health advocate and pediatrician dedicated to promoting general health and well-being.

The blog covers a wide range of topics related to health and wellness, with articles organized into several categories.

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