9 Sirolimus Side Effects You Should Know About

Sirolimus (Rapamune) is an immunosuppressant, a type of medication that lowers immune system activity. It’s prescribed to prevent organ rejection in kidney transplant recipients. But it’s also FDA approved to treat lymphangioleiomyomatosis, or LAM, a rare type of lung disease.

While sirolimus can be an effective treatment, it can cause certain side effects. Below, we review nine notable sirolimus side effects and what you can do to manage them. But keep in mind that this isn’t a comprehensive list. Your healthcare provider or organ transplant care team can discuss the medication’s potential side effects with you in more detail.

1. Canker sores

Canker sores are a common sirolimus side effect. These painful lesions can appear on the lips or gums, as well as the cheeks or roof of the mouth. And they can interfere with eating, drinking, and talking.

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Canker sores typically resolve on their own within 1 to 2 weeks. But there are things you can do to help speed up the healing process:

• Rinse your mouth with an alcohol-free mouthwash or salt water several times a day.

• Apply a 50-50 mixture of hydrogen peroxide and water directly to the canker sores a few times a day.

• Avoid eating spicy, acidic, and crunchy foods.

• Avoid using toothpastes with irritating ingredients, such as alcohol, sodium lauryl sulfate (SLS), and teeth-whitening substances.

There are medications available to help relieve pain from canker sores. Topical pain relievers, such as benzocaine (Anbesol), are available over the counter (OTC). Or your provider can prescribe a medication to help numb the area. “Magic mouthwash” is a prescription-only compounded medication that they may suggest.

2. Constipation or diarrhea

Many people taking sirolimus experience constipation or diarrhea. But, in clinical trials, the number of people who experienced these side effects were similar in both the placebo group and the group taking sirolimus. Constipation and diarrhea can happen for many reasons, so it can be tough to tell if the medication is causing it.

If you experience constipation, drinking more water and eating more fiber can help get things moving again. An OTC stool softener or laxative can provide additional relief if dietary changes aren’t enough.

If you experience diarrhea, you should also drink plenty of fluids. But avoiding high-fiber foods is a good idea. Foods high in fiber can be tough on your stomach when you have loose stool. You may also want to stay away from spicy, greasy, and fatty foods. OTC diarrhea medication can be a helpful option for occasional relief.

3. Headaches

Headaches are another common sirolimus side effect. These should be mild enough to be managed at home. If you’re experiencing severe or persistent headaches, let your healthcare provider know. This isn’t typical with sirolimus.

Taking certain measures can help prevent headaches, including:

• Staying hydrated

• Avoiding or limiting alcohol consumption

• Exercising regularly

• Getting enough sleep

If needed, acetaminophen (Tylenol) is an OTC pain medication that can help relieve occasional headaches. But you should avoid taking nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil, Motrin). Taking NSAIDs with sirolimus can raise your risk of kidney damage, a serious sirolimus side effect we’ll discuss below.

4. Risk of infections

Sirolimus works by weakening your immune system. This is important for it to be effective, but it can also raise your risk of infections. Urinary tract infections (UTIs) were the most common type of infection reported by people taking sirolimus in clinical trials.

Less commonly, people develop more serious infections, such as shingles. And in the most severe cases, life-threatening infections, such as sepsis, can happen.

To help lower your risk of this side effect, your healthcare provider may prescribe you medication to help prevent certain infections. For example, you may be prescribed antibiotics to help prevent certain types of pneumonia (a lung infection).

If you develop symptoms of an infection — such as fever, cough, or chills — while taking sirolimus, contact your provider. They may want to evaluate you and prescribe medication to treat your infection.

Good to know: Staying up to date on your vaccinations can help lower your risk or lessen the severity of some infections. But you should avoid live vaccines, such as the nasal flu vaccine (FluMist), while taking sirolimus.

5. Swelling in the arms and legs

Sirolimus is one of many medications that can cause swelling in the arms or legs. Because of how the medication works, it can make it harder for your body to get rid of excess fluid.

Even though swelling is a common sirolimus side effect, you should contact your healthcare provider if it happens. In severe cases, swelling can be a symptom of kidney damage. Your provider can help determine the next best steps.

6. Raised blood pressure

Raised blood pressure is another common sirolimus side effect. In some cases, people may develop hypertension (chronic high blood pressure).

Keep in mind that a similar number of people developed hypertension in both the placebo group and the group taking sirolimus in clinical trials. And other medications commonly taken after an organ transplant, such as cyclosporine (Sandimmune) and corticosteroids, can also cause this side effect.

High blood pressure typically doesn’t cause symptoms. Your healthcare provider should check your blood pressure during office visits to watch for hypertension. Depending on your personal risks, they may also ask you to check your blood pressure at home. If your blood pressure starts to get too high, they may prescribe you medication to help lower it.

7. Raised cholesterol

Sirolimus can also raise your triglyceride (fats in the blood) and cholesterol levels. The medication prevents these substances from being broken down in the body. And people who receive organ transplants already have an increased risk of high cholesterol, regardless of what medication(s) they take to prevent rejection.

Similar to high blood pressure, high cholesterol usually causes no symptoms. Your healthcare provider should check your cholesterol levels regularly while you’re taking sirolimus. If your levels go up too much, they may recommend that you take a cholesterol-lowering medication.

8. Slower wound healing

Sirolimus can limit or slow down the wound healing process. This has been shown to occur in up to 50% of kidney transplant recipients taking sirolimus. This is why healthcare providers don’t typically prescribe sirolimus by itself right after a transplant.

Slow wound healing could also be problematic if you need to have another surgical procedure done. If this is the case, make sure your surgeon and surgical care team know that you’re taking sirolimus before you have the procedure. Depending on your personal risks, they may recommend that you stop taking the medication before the surgery. They may also recommend that you switch to a different immunosuppressant until your surgical wounds heal. But don’t stop sirolimus unless a provider has told you to do so.

Beyond making surgical procedures riskier, slow wound healing can create issues if you’re injured. It’s a good idea to discuss how to manage wounds at home with your provider while taking sirolimus. They can provide you with tips on how to treat wounds and discuss when you should contact them for guidance or seek more immediate help.

9. Kidney damage

Kidney damage is a serious potential side effect of sirolimus. The good news is that it’s not very common. In fact, sirolimus is less likely to cause kidney damage than some other transplant rejection medications, such as cyclosporine.

Combining sirolimus with certain medications, such as NSAIDs, can raise your risk of kidney damage. So it’s a good idea to share your up-to-date medication list with your healthcare provider and pharmacist. This can help them manage potential interactions.

If you notice swelling in the arms or legs, or that the amount of urine you make suddenly decreases, contact your provider. These can be symptoms of kidney damage, and you may need immediate treatment.

When should I contact my healthcare provider about sirolimus side effects?

You can always contact your healthcare provider or transplant care team if you’re experiencing bothersome or concerning sirolimus side effects. It never hurts to check in if you’re unsure whether something is cause for worry. Your care team should also be watching for certain sirolimus side effects that are tricky to spot at home, such as raised blood pressure and cholesterol.

Contact your provider or care team right away if you experience any of the following:

• Symptoms of a serious infection, such as a high fever, severe fatigue, or shortness of breath

• A wound that doesn’t heal

• Swelling in the arms or legs

• Canker sores that progressively worsen or don’t heal

• A sudden decrease in how much you urinate

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Written by:

Kevin Le, PharmD, BCPS, BCPPS

Kevin Le, PharmD, BCPS, BCPPS is a clinical pharmacy specialist in solid organ transplant at Ann & Robert H. Lurie Children’s Hospital of Chicago. He has been working as a pediatric pharmacist since 2016.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

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