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Organ Transplants: Antirejection Medicines

Organ Transplants: Antirejection Medicines


People who've had an organ transplant need antirejection medicines. That's because the immune system will try to destroy the new organ. These medicines weaken your immune system and make it harder for your body to destroy your new organ. But they also make it harder for your body to fight infections, cancer, and other diseases.

Types of antirejection medicine you may need to take include:

  • Corticosteroids.
  • Calcineurin inhibitors.
  • Antiproliferative agents.
  • Monoclonal antibodies.
  • Polyclonal antibodies.

These medicines are also called immunosuppressants.


You get a dose of a steroid medicine before your transplant. These medicines include prednisone and methylprednisolone. They make your immune system less active. They also reduce inflammation and prevent rejection of the organ. For the first few days after your transplant, you'll likely have a high dose. 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 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.

Calcineurin inhibitors

Calcineurin inhibitors block the message that causes rejection. Examples include tacrolimus and cyclosporine. You probably will always need to take these medicines. Side effects include high blood pressure, too much potassium in the blood, and kidney problems. These medicines can also cause nausea, vomiting, diarrhea, high cholesterol, tremors, and seizures.

Antiproliferative agents

Antiproliferative agents prevent the immune cells from multiplying. These medicines include mycophenolate mofetil and azathioprine. They prevent your immune system from attacking and destroying the donor organ. Common side effects can include nausea, anemia, high triglycerides, and intestinal upset.

Monoclonal antibodies

Monoclonal antibodies block the growth of immune cells that are responsible for rejection. These medicines include daclizumab, basiliximab, and rituximab. They are used early after transplantation along with calcineurin inhibitors and antiproliferative agents.

Polyclonal antibodies

Polyclonal antibodies deplete the body's immune cells for a short time. These medicines include antithymocyte globulin-equine and antithymocyte globulin-rabbit. They 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, itching, and joint pain.

Related Information


Current as of: June 6, 2022

Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine

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