Afinitor (everolimus) is a brand-name prescription medication. It’s approved by the Food and Drug Administration (FDA) to treat certain types of cancers, tumors, and seizures.*

Here are some fast facts about Afinitor:

  • Active ingredient: everolimus
  • Drug class: mammalian target of rapamycin kinase inhibitor
  • Drug forms:
    • Afinitor: oral tablet
    • Afinitor Disperz: tablet for liquid suspension (a tablet that you’ll dissolve in water and then swallow)

Like other drugs, Afinitor can cause side effects. Read on to learn about potential common, mild, and serious side effects. For a general overview of Afinitor and Afinitor Disperz, including details about their uses, see this article.

* For detailed information on the conditions Afinitor and Afinitor Disperz are prescribed to treat, see our comprehensive article on the drugs.

Afinitor can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist. It’s also important to note that the side effects may vary based on what condition you’re taking the drug for.

These are just a few of the more common side effects reported by people who took Afinitor in clinical trials.

* To learn more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Afinitor. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Afinitor’s prescribing information.

Mild side effects that have been reported with Afinitor include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Afinitor and want to tell the FDA about it, visit MedWatch.

* To learn more information about this side effect, see “Side effect specifics” below.

Afinitor may cause serious side effects in some people. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Afinitor’s prescribing information.

If you develop serious side effects while taking Afinitor, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

* To learn more information about this side effect, see “Side effect specifics” below.

In general, the side effects of Afinitor in children are similar to those seen in adults.

However, in clinical trials, mild and serious infections were more common in children younger than 6 years old compared with older children. In rare cases, serious infections have led to death.

Talk with your child’s doctor if you have questions about their risk of infections.

Afinitor may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Is hair loss one of Afinitor’s side effects?

No, hair loss shouldn’t occur as a side effect of Afinitor if it’s taken by itself.

Hair loss can be a side effect when Afinitor is taken with a drug called exemestane. Exemestane is taken with Afinitor to treat certain types of breast cancer.

If you have questions about hair loss and your treatment plan, talk with your doctor.

Are there any side effects specific to the 10-milligram (mg) strength of Afinitor?

No. Afinitor may cause mild or serious side effects at any dose. The dosage your doctor prescribes will depend on several factors. These may include the condition that’s being treated or your height and weight.

If you develop bothersome side effects while taking the 10-mg strength of Afinitor, your doctor may adjust or lower your dosage.

For more information about dosage and dosage adjustments, see this article. You can also talk with your doctor or pharmacist.

What side effects should I expect when taking Afinitor for breast cancer?

Afinitor’s side effects can vary based on which condition is being treated. In clinical trials for breast cancer treatment, the more common side effects were mouth sores, infection, and skin rash. (For additional information, see the “More common side effects” section above.)

Is neuropathy a possible side effect of Afinitor?

No, Afinitor shouldn’t cause neuropathy. Neuropathy is nerve damage that causes symptoms such as pain, numbness, and tingling. This side effect wasn’t seen in people who took Afinitor in clinical trials.

To treat cancer, doctors may prescribe other medications along with Afinitor. These other medications may cause neuropathy. For example, Afinitor was given with bortezomib (the generic version of Velcade) and Rituxan (rituximab) to treat a form of lymphoma* in a clinical trial. Neuropathy was reported as a side effect in this trial.

Talk with your doctor if you have symptoms of neuropathy while taking Afinitor. They may want to look at other possible causes, including any other medications you’re taking.

* Afinitor is not currently approved by the Food and Drug Administration (FDA) to treat lymphoma. However, the drug may be prescribed off-label to treat this condition. Off-label drug use is when an FDA-approved drug is prescribed for a purpose other than what it’s approved for. To learn about the cancers that Afinitor is approved to treat, see this article.

Learn more about some of the side effects that Afinitor may cause.

Mouth sores

Mouth sores are common while taking Afinitor, especially in the first 8 weeks of treatment. This was the most common side effect seen in clinical trials.

This side effect may cause:

  • ulcers or sores inside your mouth or on your lips
  • pain and inflammation (swelling and damage) inside your mouth
  • a burning sensation or redness of your gums or tongue
  • trouble talking or swallowing, in severe cases

What you can do

Your doctor may prescribe dexamethasone oral solution to help prevent or treat mouth sores from Afinitor. This solution is a liquid that you’ll rinse your mouth with and spit out.

You can also try to soothe mouth sores with an over-the-counter (OTC) mouthwash. However, some products can make mouth sores worse. Be sure to avoid using products that contain the following ingredients:

It may also be helpful to limit hot or spicy foods. You should also try to avoid acidic foods, such as citrus, and foods that contain thyme.

If you have mouth sores from Afinitor, tell your doctor if they bother you or become severe. Depending on the severity of your symptoms, your doctor may have you stop taking Afinitor. They’ll determine whether to restart your treatment. If they do, it’ll likely be at a lower dosage. (For more information about dosage, see this article.)

Skin rash

A skin rash can be a side effect of Afinitor. Skin rash was commonly seen in people who took the drug in clinical trials. In most cases, this side effect was mild.

A rash can also be a sign of a serious side effect, such as an infection or an allergic reaction. However, serious side effects are less common.

What you can do

If you develop a mild skin rash while taking Afinitor, your doctor may prescribe you an OTC product to treat it. Make sure to check with your doctor before using any other treatments to make sure it’s safe for you to use.

If the rash doesn’t go away or becomes severe, talk with your doctor. They may recommend other ways to relieve this side effect. Or they may have you pause or stop treatment with Afinitor.

Mild or serious infection

Mild or serious infections can occur while taking Afinitor. Mild infections were more commonly reported in clinical trials than serious infections. Serious infections, such as pneumonia or reactivation of existing hepatitis B virus, are possible. In rare cases, serious infections may lead to death.

Symptoms can vary depending on the type of infection, but generally may include:

Certain groups of people may be more likely to get infections while taking Afinitor. These include children under the age of 6 years old and adults ages 65 years and older.

What you can do

It’s important to take steps to reduce your risk of getting infections while taking Afinitor. These include washing your hands and avoiding close contact with people who may have contagious infections.

It’s also important to talk with your doctor before getting any vaccines during Afinitor treatment. Due to the risk of infection, live vaccines* aren’t safe for you to receive while taking Afinitor. Also, you should avoid close contact with people who’ve recently received live vaccines.

If you develop symptoms of an infection or if you generally don’t feel well, tell your doctor right away. If they think you have a serious infection, you may need treatment in a hospital. Depending on the severity, your doctor may have you pause or stop treatment with Afinitor.

* Live vaccines contain a weakened form of the pathogen that the vaccine is meant to protect you from. See the “Precautions for Afinitor” section below for details about vaccines during Afinitor treatment.

Metabolic syndrome

Metabolic syndrome is a common side effect of Afinitor. The drug may cause changes in your metabolism, including the way your body breaks down sugars and fats. Over time, these changes can lead to metabolic syndrome. This means that you have a group of risk factors linked to an increased risk of cardiovascular disease and type 2 diabetes.

Metabolic syndrome with Afinitor may include:

High cholesterol or triglyceride levels don’t typically cause symptoms. However, hyperglycemia may cause symptoms, such as increased thirst, frequent urination, blurred vision, or tiredness. If you have diabetes or high cholesterol, taking Afinitor may make your condition worse or harder to manage.

What you can do

While taking Afinitor, your doctor may monitor you for changes in your metabolism. To do this, they may have you get blood tests regularly. If you have diabetes, they may also have you check your blood sugar more often.

If you develop metabolic syndrome, including if your blood sugar, cholesterol, or triglyceride levels become high, your doctor may recommend medications to manage this. They may also recommend changes in your diet.

If metabolic syndrome with Afinitor becomes severe, your doctor may have you stop taking the drug. Your treatment will likely be stopped until your symptoms ease. If your doctor recommends restarting treatment, they may start you on a lower dosage. (For more information about dosage, see this article.)

Allergic reaction

As with most drugs, Afinitor can cause an allergic reaction in some people. Severe allergic reactions were rare in clinical trials.

Allergic reaction symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Afinitor. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Afinitor. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. The conditions and factors to consider include:

Upcoming surgery. Surgical wounds may not heal correctly while you’re taking Afinitor. If you plan to have surgery, talk with your doctor. They’ll likely have you stop taking Afinitor at least 1 week before your surgery. Depending on how well your wound heals after surgery, they’ll let you know when you can resume Afinitor treatment.

Radiation. Afinitor can worsen side effects from radiation therapy. If you’re having radiation, talk with your doctor. They’ll discuss the possible risks and benefits of adding Afinitor to your treatment plan.

Kidney problems. Taking Afinitor can cause kidney problems, including kidney failure, in rare cases. You may be at higher risk of this side effect if you have preexisting kidney problems. Be sure to talk with your doctor before you start taking Afinitor. They can determine if Afinitor is safe for you. If they prescribe Afinitor to you, they may monitor your kidney function closely during treatment.

Liver problems. If you have liver damage or liver disease, your body may not get rid of Afinitor correctly. This may increase the risk of side effects. Be sure to tell your doctor about any liver problems you have before taking Afinitor. They’ll likely prescribe a lower dosage of Afinitor for you. (For more information about dosage, see this article.)

Diabetes. Afinitor may cause changes in the way your body metabolizes (breaks down) sugar.* This can lead to hyperglycemia (high blood sugar). If you already have diabetes, taking Afinitor may make it harder to manage your blood sugar. Your doctor may recommend changes to your diabetes treatment while taking Afinitor. They may also have you adjust how often you monitor your blood sugar.

Infections, including hepatitis B. Taking Afinitor can increase your risk of an infection.* If you’ve had hepatitis B in the past, taking the drug may reactivate the virus that causes this infection. This can cause its symptoms to return. Before your doctor prescribes Afinitor, they may check and treat any infections you have.

High cholesterol or triglycerides. Afinitor may cause changes in the way your body metabolizes fats.* This can lead to high levels of fats, such as cholesterol and triglycerides, in your blood. If you already have high cholesterol or high triglycerides, taking Afinitor may worsen your condition. Your doctor may recommend changes to your treatment plan while taking Afinitor.

Live vaccines. Afinitor weakens the immune system. So during treatment, it isn’t safe to receive live vaccines or be around people who’ve recently received a live vaccine. (Live vaccines contain a weakened form of the pathogen that the vaccine is meant to protect you from.) Receiving a live vaccine while taking Afinitor increases your risk of becoming infected, instead of protected, by the vaccine.

Ask your doctor about any vaccines that you should receive before starting Afinitor treatment. And before getting any vaccines while taking Afinitor, you should check with a healthcare professional to confirm that it isn’t live. Examples of live vaccines include the measles, mumps, and rubella vaccine and the chickenpox vaccine.

Allergic reaction. If you’ve had an allergic reaction* to Afinitor or any of its ingredients, your doctor will likely not prescribe Afinitor for your condition. Ask your doctor what other medications may be better options for you.

* For more information, see the “Side effect specifics” section above.

Alcohol with Afinitor

Alcohol isn’t known to cause any drug interactions with Afinitor. However, drinking a lot of alcohol can increase the risk of liver problems. And it may not be safe to take Afinitor if you have liver problems.

You should also avoid using mouthwash that contains alcohol while taking Afinitor. Doing so may cause mouth soresfrom Afinitor or make them worse. Mouth sores are a common side effect of the drug. (For more information, see the “Side effects specifics” section above.)

If you have questions about alcohol and Afinitor, talk with your doctor.

Pregnancy and breastfeeding while taking Afinitor

Afinitor is not safe to take during pregnancy. The drug hasn’t been studied in humans. However, Afinitor treatment caused fetal harm (commonly known as “birth defects”) and pregnancy loss in animal studies.

If you are able to become pregnant, your doctor will recommend you use birth control during and after Afinitor treatment. Females* should continue using birth control for 8 weeks after their last dose. And males* with partners who can become pregnant should continue using birth control for 4 weeks after their last dose.

It isn’t safe to take Afinitor while breastfeeding. You should not breastfeed while taking Afinitor or for 2 weeks after your last dose. The drug hasn’t been studied in people who are breastfeeding. However, animal studies have shown that a high amount of Afinitor passes into breast milk.

If you have questions about pregnancy or feeding options while taking Afinitor, talk with your doctor.

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Not everyone who takes Afinitor develops side effects. However, mild or serious side effects can occur. If you’d like to learn more about Afinitor, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.