Entyvio (vedolizumab) is a brand-name prescription medication that’s prescribed to treat active ulcerative colitis and Crohn’s disease. Entyvio can cause side effects that range from mild to serious, including a rare brain infection.

Entyvio 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.

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

Which side effects are more common doesn’t change depending on which condition Entyvio treats.

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

Mild side effects can occur with Entyvio. These are the same regardless of which condition Entyvio treats. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Entyvio’s prescribing information.

Mild side effects that have been reported with Entyvio 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 being treated with Entyvio and want to tell the FDA about it, visit MedWatch.

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

Entyvio may cause serious side effects.

If you develop serious side effects during Entyvio treatment, 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.

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

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

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

Allergic reaction

For some people, Entyvio can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Entyvio, your doctor may recommend a different medication instead.

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

What are Entyvio’s long-term side effects?

It’s possible for Entyvio treatment to cause long-term side effects. This includes liver damage, which is a rare side effect of Entyvio. If liver damage, such as hepatitis, does occur, it may cause long-term symptoms. For more information, see the “Serious side effects of Entyvio” section.

Progressive multifocal leukoencephalopathy (PML) wasn’t reported as a side effect in Entyvio’s clinical trials. However, one case of PML was reported after Entyvio became available for use. PML is a very rare but serious brain infection. Developing PML during Entyvio treatment is also very rare. However, it can cause long-term disability in some people. To learn more, see “Side effect specifics.”

If you have additional questions about long-term side effects and Entyvio, talk with your doctor or pharmacist.

Does Entyvio cause cancer?

No, Entyvio doesn’t cause cancer. In the drug’s studies, treatment with Entyvio did not appear to increase a person’s risk of cancer.

However, Entyvio can cause liver damage. In some cases, liver damage may increase the risk of developing liver cancer. Due to the risk of liver damage, doctors likely won’t prescribe Entyvio if you already have a serious liver problem.

If you have concerns about how Entyvio may affect your specific risk of cancer, talk with your doctor. They can help you understand your cancer risk factors and make sure Entyvio is safe for you to receive.

Is hair loss a side effect of Entyvio?

No, hair loss isn’t a known side effect of Entyvio. It wasn’t reported in the drug’s clinical trials.

However, hair loss is common in people with inflammatory bowel disease (IBD).

Entyvio is prescribed to treat Crohn’s disease and ulcerative colitis (UC), which are two types of IBD. Other medications prescribed to treat these conditions may cause hair loss. However, this hasn’t been seen with Entyvio treatment.

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

Should I expect weight gain during Entyvio treatment?

Possibly. Weight gain wasn’t a side effect reported in clinical trials of Entyvio. However, mild weight gain has been reported since Entyvio became available for use.

Weight gain during Entyvio treatment may be the result of being able to eat more food than before. This is because Entyvio treatment is meant to relieve symptoms of CD or UC or induce remission. (During remission, symptoms go away.) With fewer symptoms, you may eat more food than you did when you experienced symptoms. This could lead to weight gain.

Other medications that treat CD or UC may also cause weight gain. These include corticosteroids such as prednisone.

If you have concerns about weight gain while you’re receiving Entyvio treatment, talk with your doctor. They can suggest ways to maintain a weight that’s healthy for you.

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

Brain infection

Progressive multifocal leukoencephalopathy (PML) is a rare but serious viral infection of the brain.

PML wasn’t seen in clinical trials of Entyvio. However, one known case of PML has been reported since the drug became available for use. PML has also been reported in people taking a drug called natalizumab (Tysabri), which works in a similar way to Entyvio.

Symptoms of PML can include:

  • blurry vision or vision loss
  • changes in how you talk or walk
  • confusion or trouble thinking clearly
  • loss of balance
  • weakness or loss of strength on one side of your body

What you can do

Your doctor will monitor you for symptoms of PML while you’re receiving treatment with Entyvio. Talk with your doctor right away if you develop any of the symptoms listed above. They will investigate your symptoms and guide you on the next steps.

Infusion reaction

Entyvio may cause side effects after or during an infusion in some people. The drug is given by a healthcare professional as an IV infusion. Drugs that are given this way may cause an infusion reaction (side effects that occur during or shortly after an infusion).

Infusion reactions reported in clinical trials of Entyvio include:

In most people, these reactions were mild or moderate. Rarely, a severe allergic reaction may occur during or shortly after an infusion of Entyvio. For more information on symptoms of allergic reaction, see the “Allergic reaction” section.

Infusion reaction wasn’t a common side effect of Entyvio in clinical trials. And how often this side effect occurred didn’t vary based on whether Entyvio was given for Crohn’s disease or ulcerative colitis.

What you can do

You’ll receive Entyvio infusions at your doctor’s office, an infusion clinic, or a similar setting. A healthcare professional will monitor you during each infusion. If you develop symptoms of an infusion reaction, they’ll have treatments ready to give you.

Infusion reactions can also happen after your infusion, usually within 2 hours. Be sure to tell your doctor right away if you experience infusion reaction symptoms. Depending on the severity of your reaction, they may stop your treatment with Entyvio.

If your doctor determines that you’re having an infusion reaction, they may give you certain medications before your next infusion. This can help prevent or minimize infusion reactions from Entyvio.

Skin itchiness and rash

Treatment with Entyvio can cause skin itchiness and rash. In Entyvio’s clinical trials, this was one of the most commonly reported side effects.

In most cases, these side effects are mild. However, itchiness and rash may also be a symptom of a more serious side effect. This may include an infusion reaction or an allergic reaction. (See “Infusion reaction” and “Allergic reaction” to learn more.)

What you can do

Because skin itchiness and rash may be a sign of a more serious reaction to Entyvio, you should tell your doctor right away if you notice these side effects.

If you develop itchiness or a rash during an Entyvio infusion, you’ll be treated at the office or clinic where you receive your infusions.

If these side effects happen after your infusion, make sure to contact your doctor right away. They may want to examine your symptoms in person. If your doctor determines that you’re having an infusion reaction, they may give you certain medications before your next infusion. This can help prevent skin itchiness and rash.

Nausea

Nausea may occur as a side effect of treatment with Entyvio. Nausea was a more common side effect in clinical trials of Entyvio. In most cases, nausea from Entyvio is mild.

What you can do

If nausea happens during your Entyvio infusion, your doctor will give you a treatment in the office or clinic. They may also give you medication before your next infusion to help prevent nausea.

If this side effect doesn’t go away or becomes severe, talk with your doctor. They may switch you to a different medication for your condition. They may also want to check you for other causes of nausea.

Pain in joints

Some people may experience joint pain as a side effect of Entyvio. This was among the more common side effects in clinical trials.

What you can do

Tell your doctor if you have joint pain while being treated with Entyvio. They may suggest a treatment for this side effect. This can include topical medications or a nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen (Advil, Motrin).

If you have joint pain that’s bothersome or won’t go away, your doctor may recommend stopping treatment with Entyvio. They will prescribe another medication for your condition.

Before receiving Entyvio, discuss your health history with your doctor. Entyvio may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

If you’d like to learn more about Entyvio, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from treatment with 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.