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Immunosuppressants work by suppressing, or weakening, your immune system so that it will not reject your transplant organ.


Many different immunosuppressants can be used after a transplant. In order of use (most frequent to least frequent), the six most common immunosuppressant medications are:

No matter which immunosuppressant you’re taking, it is important to take it safely and know how to manage your doses of immunosuppressants.

Taking immunosuppressants safely

Many medicines can change the way immunosuppressants works in your body. Some raise the medicine levels in your blood, which can lead to more side effects, and others lower the level, which may lead to a rejection of the organ.

Taking immunosuppressants with other medicines

Always call your transplant team before using any new medicines, whether:

  • your doctor prescribes them
  • you buy them “over the counter” at a drugstore
  • they are herbal or natural medicines.

Some immunosuppressants cannot be used at the same time, as you can see in the table below.

Tacrolimus​is never taken withcyclosporine
Mycophenolateis never taken withazathioprine
Azathioprineis never taken withmycophenolate
is never taken withtacrolimus

Managing your doses of immunosuppressants

What to do if you miss a dose of medication

  • Take the missed dose as soon as you remember.
  • If it is almost time for the next dose, skip the missed dose. Take the next dose at the regular time.
  • Never take two doses to make up for the missed dose.
  • Call your transplant team if you have missed more than one dose or if you generally find it hard to remember your doses.

What to do if you vomit a dose of medication

When you take a dose of medication, it usually passes your stomach into your blood within an hour. The transplant pharmacist will talk with you about this after your transplant.

  • If you throw up more than an hour after taking your immunosuppressant: there is no need to repeat the dose.
  • If you throw up less than an hour after taking the immunosuppressant: ask your transplant team if you need to repeat the dose. We will decide based on what is going on with you at that time (for example if you are sick, how long ago you received your transplant, if you recently had a rejection and so on).
  • If you repeat a dose, and you throw that up as well, do not repeat it again.

Keep track of any vomited or repeated doses and talk to your transplant team or family doctor if you are vomiting a lot. Use this chart to help you decide when to call for advice.

You may not feel like eating or drinking when you are vomiting. But you risk becoming dehydrated if you do not drink.

If you normally take immunosuppressants with food but are not eating because you are vomiting, more medication might pass from your stomach into your bloodstream. This depends on the immunosuppressant(s) you are taking, so speak to your transplant team for advice.

Having higher levels of immunosuppressant in your blood will expose you to more side effects.

What to do if you have diarrhea (watery stools)

Diarrhea (watery stools) can change the amount of immunosuppressant that passes from your stomach into your blood. This could lead to immunosuppressant levels that are too high or too low. Frequent diarrhea can also cause you to become dehydrated. This chart will help you decide if you need to contact your transplant team or family doctor for help with managing diarrhea.

What to do if someone else takes your immunosuppressant

Call your local poison information centre.

If you live in Ontario, call the Ontario Poison Centre. The calls are free.

  • Call 416-813-5900 if you live in Toronto.
  • Call 1-800-268-9017 if you live somewhere else in Ontario.

How to prevent infections

As you know, immunosuppressants weaken your immune system, which increases your chance of getting an infection.

You can prevent infections by following these steps.

  • Wash your hands with soap and water often, especially if you are in a public place.
  • Avoid people with infections such as a cold or the flu.
  • Keep good dental hygiene by flossing and brushing your teeth regularly. Make sure you have regular dental check-ups.
  • Follow food handling guidelines and make safe food choices.
  • Get a flu shot every year (wait four to six months after your transplant for the first one).
  • Make sure that your routine vaccines​ (“shots”) are up to date. Check with your transplant team if you are unsure which shots you can have.
Last updated: November 30th 2017