Ocrevus (ocrelizumab) is a brand-name biologic solution prescribed for multiple sclerosis and clinically isolated syndrome. As with other drugs, Ocrevus can cause side effects, such as infusion side effects and certain cancers.

Specifically, Ocrevus is approved to treat the following conditions in adults:

Ocrevus belongs to the monoclonal antibody drug class. A healthcare professional will administer it as an IV infusion.

Read on to learn about potential common, mild, and serious side effects. For a general overview of Ocrevus, including details about its uses, see this article.

Side effects of Ocrevus can vary depending on which condition the drug is used to treat. These are just a few of the more common side effects reported by people who took Ocrevus in clinical trials.

More common side effects in people taking Ocrevus (regardless of the condition being treated) include:

In people who have either a relapsing form† of multiple sclerosis (MS) or clinically isolated syndrome (CIS), the following side effects were also more common:

Finally, in people taking Ocrevus for primary progressive MS (PPMS), the following side effects were more common:

  • cough
  • diarrhea
  • skin infections*

* For more information about this side effect, see “Side effect specifics” below.
† Relapsing forms of MS that Ocrevus is used to treat include active secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS).

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

Mild side effects reported in people taking Ocrevus for a relapsing form* of multiple sclerosis (MS) or for clinically isolated syndrome (CIS) include:

Mild side effects in people taking Ocrevus for primary progressive MS (PPMS) include:

  • herpes infections, such as oral herpes or shingles
  • cough
  • diarrhea
  • swelling in your arms or legs
  • upper or lower respiratory infections,† such as the common cold or pneumonia
  • skin infections†

These side effects may be temporary, lasting a few days or weeks. But 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 Ocrevus and want to tell the FDA about it, visit MedWatch.

* Relapsing forms of MS that Ocrevus is used to treat include active secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS).
† For more information about this side effect, see the “Side effect specifics” section below.

Ocrevus may cause serious side effects, although this wasn’t very common in clinical trials. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Ocrevus’s prescribing information.

If you develop serious side effects while taking Ocrevus, 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 reported with Ocrevus and their symptoms include:

  • Colitis (inflammation of the colon). Symptoms can include:
    • abdominal pain or cramping
    • diarrhea
    • blood in your stool
  • Increased risk of certain infections, including the herpes infection, if you are exposed to the virus. Symptoms of a serious herpes infection can include:
  • Progressive multifocal leukoencephalopathy (PML). Symptoms can include:
    • general weakness that steadily gets worse
    • balance issues
    • changes to vision
    • memory problems and mental slowness
  • Reactivation of existing hepatitis B. Symptoms can include:
    • jaundice (yellowing of the skin or the whites of your eyes)
    • confusion
    • dark urine or stools that are darker than usual
    • fatigue or drowsiness
    • nausea or vomiting, including vomiting blood
    • pain or swelling in the upper-right side of your abdomen
  • Infusion side effects.*
  • Cancer.*
  • Allergic reaction.*†

* For more information about this side effect, see the “Side effect specifics” section below.
† An allergic reaction is possible after receiving Ocrevus. But this side effect wasn’t reported in clinical trials.

Most side effects from Ocrevus are mild and go away after a few days. However, some side effects may last long term and continue to cause symptoms after stopping Ocrevus.

For example, Ocrevus can increase your risk of skin infections. Your risk of skin infections will remain increased for as long as you receive Ocrevus. Certain infections, such as herpes infection, may last for longer than a year after you stop treatment.

In addition, Ocrevus may increase your risk for cancer, including breast cancer. Breast cancer may cause symptoms that last long term. The duration of this condition depends on several factors such as the type of breast cancer.

For more information about these risks, see the “Side effect specifics” section below.

If you experience side effects that don’t go away, call your doctor. They can determine whether Ocrevus is safe or whether you should try a different medication.

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

Infusion side effects

Infusion side effects can occur during or up to 24 hours after an Ocrevus infusion. This may also be called an infusion reaction.

Examples of infusion side effects that Ocrevus can cause include:

  • headache
  • fatigue
  • trouble breathing
  • increased heart rate
  • skin itchiness, redness, or discoloration
  • mouth pain or swelling

Your doctor or another healthcare professional will monitor you for at least 1 hour after you have an Ocrevus infusion. This is to watch for infusion side effects.

What you can do

If you notice symptoms of infusion side effects after an Ocrevus infusion, talk with your doctor right away. Even mild reactions can become serious quickly and may require urgent treatment.

If you experience side effects during an infusion, your infusion may be slowed down or stopped. Depending on the severity of your reaction, a healthcare professional may administer your next infusion more slowly, over a longer period. You may also be given other medications before your next infusion to reduce the risk of a reaction. These medications may include Medrol (methylprednisolone) and Tylenol (acetaminophen).

If you have a very severe reaction, your doctor may have you permanently stop Ocrevus treatment and switch to a different medication.

Cancer

Taking Ocrevus may increase your risk for cancer, including breast cancer. People who took the drug in clinical trials had a higher rate of cancer development than people who took a placebo or a similar drug. (A placebo is a treatment with no active drug.)

What you can do

Based on your risk factors for cancer, your doctor will recommend how often you should receive cancer screening throughout Ocrevus treatment.

Symptoms of cancer vary, depending on the type of cancer. For example, symptoms of breast cancer may include:

  • a lump in your breast
  • discharge from your nipple
  • pain in your breast or nipple

Talk with your doctor about symptoms of cancer that you may need to monitor for while taking Ocrevus.

Upper and lower respiratory infections

Upper and lower respiratory infections are two of the most common side effects reported by people taking Ocrevus in clinical trials. Upper respiratory infections (such as the common cold) were more common than lower respiratory infections (such as pneumonia).

Symptoms of a respiratory infection can include:

  • cough
  • fever
  • chills

Most people who had an upper or lower respiratory infection while taking Ocrevus had mild cases. But in rare cases, these infections can be severe.

What you can do

If you have an active infection before starting Ocrevus, you will need treatment for the infection, or you’ll have to wait until it resolves before starting Ocrevus. This includes an upper or lower respiratory infection.

If you develop symptoms of an infection while taking Ocrevus, call your doctor. They’ll likely want to evaluate your symptoms further. If they diagnose an infection, they may prescribe antibiotics to treat it. They may also recommend treatments for any symptoms you’re experiencing.

A simple but effective way to help prevent infection includes washing your hands. It is essential to do this regularly, especially during Ocrevus treatment. For tips on how to properly wash your hands, check out this article.

Skin infections

Skin infections are a possible side effect of Ocrevus. In clinical trials, they were more common when the drug was taken to treat primary progressive multiple sclerosis (PPMS) than when it was used for relapsing forms* of multiple sclerosis (MS) or for clinically isolated syndrome (CIS). But, skin infections may occur in people taking the drug for any type of MS.

Symptoms of a skin infection can include:

  • discoloration
  • swelling
  • pain
  • skin that’s warmer than usual
  • rash

Most people who experienced skin infections while taking Ocrevus had mild cases. But in rare cases, these infections can be severe.

* Relapsing forms of MS that Ocrevus is used to treat include active secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS).

What you can do

If you have symptoms of a skin infection while taking Ocrevus, call your doctor. They may want to examine you. If you do have a skin infection, your doctor may prescribe antibiotics or other treatments.

A simple but effective way to help prevent infection includes handwashing. You should do this regularly. For tips on how to properly wash your hands, check out this article.

Pain in your arms, back, or legs

It’s possible to experience pain in your arms, back, or legs while taking Ocrevus. This was a mild side effect that was somewhat common among people taking the drug in clinical trials.

People taking Ocrevus for relapsing forms* of MS or for CIS were more likely to have this side effect than people taking Ocrevus for PPMS.

It’s important to note that pain in your arms, back, or legs can also be a symptom of MS.

* Relapsing forms of MS that Ocrevus is used to treat include active secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS).

What you can do

Call your doctor if you develop any pain in your back, legs, or arms while taking Ocrevus. They may want to see you to help determine the cause of your pain, and they may recommend treatment. The doctor may also have you try a medication other than Ocrevus for your condition.

Allergic reaction

As with most drugs, Ocrevus can cause an allergic reaction in some people. But this side effect wasn’t reported in clinical trials.

Symptoms of a reaction can be mild or serious and can include:

  • rash
  • itching
  • flushing
  • swelling under your skin, typically in your lips, eyelids, feet, or hands
  • 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 continue Ocrevus treatment. But if your symptoms are serious, and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

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

Does Ocrevus cause weight gain?

No, Ocrevus hasn’t been reported to cause weight gain.

However, in clinical trials, some people taking Ocrevus for primary progressive multiple sclerosis (PPMS) reported swelling in their arms and legs. Sometimes, this swelling can cause weight gain. If you experience swelling while taking Ocrevus, talk with your doctor. They may recommend a medication to help treat this side effect.

If you’re concerned about weight gain that isn’t due to swelling, talk with your doctor. They can recommend ways to maintain a weight that’s healthy for you.

Can Ocrevus cause hair loss?

It’s unlikely. Hair loss wasn’t reported as a side effect by people taking Ocrevus in clinical trials.

If you have additional questions about Ocrevus and possible effects on your hair, including hair loss, talk with your doctor.

Should I expect joint pain during Ocrevus treatment?

It’s possible that joint pain may occur with Ocrevus.

Joint pain wasn’t reported as a side effect of the drug in clinical trials. However, there have been reports of pain in people taking Ocrevus since the drug was approved. This includes pain in areas that contain joints, such as the arms and legs. For more information about pain with Ocrevus, see the “Side effect specifics” section above.

If you’re having joint pain with Ocrevus, talk with your doctor.

How long do side effects from Ocrevus last?

Most side effects from Ocrevus are mild and go away after a few days. If you experience side effects that don’t go away, call your doctor. They can determine whether Ocrevus is safe or whether you should try a different medication.

How will I feel after Ocrevus infusion?

It depends. Some people may not experience side effects with Ocrevus, but other people can experience side effects that range from mild to serious.

A more common side effect in people taking Ocrevus includes infusion side effects. Examples of infusion side effects include fatigue and skin reactions at the infusion site (such as redness, discoloration, or swelling). For more information about infusion side effects, see the “Side effect specifics” section above.

If you’re concerned about how you’ll feel after receiving Ocrevus, talk with your doctor.

Be sure to talk with your doctor about your health history before receiving Ocrevus. 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:

Active infection: If you currently have an infection, your doctor will likely treat it before you start Ocrevus treatment. This is because Ocrevus may weaken your immune system. And this can affect how well your body is able to fight infections. Make sure to tell your doctor if you have an infection before you start Ocrevus treatment.

Recent live vaccines: After receiving a live vaccine, wait at least 4 weeks before you start Ocrevus treatment. Live vaccines contain a small amount of weakened live virus or bacteria. Examples include the chickenpox vaccine and the measles, mumps, and rubella vaccine. Ocrevus may weaken your immune system, and live vaccines can cause infection in people with weakened immune systems.

Hepatitis B: If you have a history of hepatitis B, talk with your doctor before starting Ocrevus treatment. If you test positive for hepatitis B, you’ll need treatment before you start Ocrevus. This is because Ocrevus can cause reactivation of existing hepatitis B. And this can lead to serious side effects, such as liver problems. While you receive Ocrevus, your doctor may monitor you more closely if you have a history of hepatitis B.

Allergic reaction: You should not receive Ocrevus treatment if you’ve ever had an allergic reaction to this medication or any of its ingredients. Talk with your doctor about which other treatments are better choices for you.

Alcohol with Ocrevus

There are no known interactions between Ocrevus and alcohol.

If you have questions about drinking alcohol during Ocrevus treatment, talk with your doctor.

Pregnancy and breastfeeding while taking Ocrevus

Below is information about pregnancy and breastfeeding during Ocrevus treatment.

Pregnancy: If you’re pregnant or planning to become pregnant, talk with your doctor before you start Ocrevus treatment. They’ll likely recommend a treatment other than Ocrevus for you. This is because it isn’t known if Ocrevus is safe to receive during pregnancy.

If you’re pregnant and receiving Ocrevus, you can join a pregnancy registry. This tracks the health of babies born to people who used medications such as Ocrevus during their pregnancy. You can find more information about the registry here.

Breastfeeding: It isn’t known if Ocrevus passes into human breast milk or if the drug may affect a breastfed child. If you’re breastfeeding, talk with your doctor about the best way to feed your child while you’re receiving treatment for multiple sclerosis (MS) or clinically isolated syndrome (CIS).

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.