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Organ Transplants: Antirejection Medicines

Topic Overview

People who have had an organ transplant need anti-rejection medicines. This is because the immune system will try to destroy the new organ. These medicines are also called immunosuppressants. They weaken your immune system and decrease your body's ability to destroy your new organ. But they also decrease how well your body can fight infections, cancer, and other diseases.

Here are some of the medicines you may need to take. You may have to take other medicines to prevent infection or to control other health problems you have (like high blood pressure).


A high dose of a steroid medicine is given right before your transplant. It decreases your immune system's activity. It also reduces inflammation and prevents rejection. A high dose is usually continued after your surgery. Then the dosage is slowly reduced to the lowest dose that helps prevent rejection.

Taking steroid medicine for just a few days may cause short-term side effects. These include stomach upset, facial swelling, fluid retention, high blood sugars, acne, thinning of skin, high blood pressure, weight gain, sleep problems, and anxiety. High doses can sometimes cause more severe side effects, such as extreme agitation, paranoia, psychosis, and hallucinations.

Using steroid medicine for a long time can cause glaucoma or steroid-induced diabetes, osteoporosis, and slowed growth in children.

These medicines include prednisone or methylprednisolone.

Calcineurin inhibitors

These medicines block the message that causes rejection. You probably will always need to take calcineurin inhibitors.

Side effects include high blood pressure, too much potassium in the blood (hyperkalemia), diabetes, and kidney problems. These medicines can also cause nausea, vomiting, diarrhea, high cholesterol, swelling of gums, increased hair growth, tremors, and seizures.

These medicines include tacrolimus and cyclosporine.

Antiproliferative agents

These medicines prevent the immune cells from multiplying. They prevent your immune system from attacking and destroying the donor organ.

Common side effects can include nausea, anemia, fluid retention, and intestinal upset.

These medicines include mycophenolate, azathioprine, and sirolimus.

Sirolimus causes some common side effects in addition to those listed above. These include mouth sores, increased wound healing time, and high triglycerides.

Monoclonal antibodies

These antibodies block the growth of immune cells that are responsible for rejection. They are given through an intravenous (IV) and are used early after transplantation along with calcineurin inhibitors and antiproliferative agents.

These medicines include basiliximab and rituximab.

Polyclonal antibodies

These medicines deplete the body's immune cells for a short time. They are given through an intravenous (IV) and are used in the hours and days right after your organ transplant. They prevent your body from rejecting the donor organ. They may also be used again if your body starts to reject the donor organ.

They are often used to reduce early use of calcineurin inhibitors, which can have serious side effects. Side effects of polyclonal antibodies include fever, chills, leukopenia, itching, and joint pain.

Anti-thymocyte globulin-rabbit is primarily used in solid organ transplant in Alberta.

Related Information


Adaptation Date: 8/20/2021

Adapted By: Alberta Health Services

Adaptation Reviewed By: Alberta Health Services

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