Rebif (interferon beta-1a) is a brand-name injection that’s prescribed for certain types of multiple sclerosis (MS). As with other drugs, Rebif can cause side effects, such as injection site reactions, flu-like symptoms, and abdominal pain.

Rebif 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 used Rebif in clinical trials:

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

Mild side effects that have been reported with Rebif include:

  • flu-like symptoms
  • abdominal pain
  • increased liver enzymes
  • fever
  • fatigue
  • back pain
  • muscle aches
  • vision changes
  • injection site reactions*

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 and reviews side effects of the medication. It’s important to let the FDA know if you experience any side effects while using Rebif. Sharing your experience helps make medications safer for everyone by giving doctors and researchers more information about how the drug works in real life. You can report side effects to the FDA MedWatch program by visiting the MedWatch website or calling 800-FDA-1088.

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

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

If you develop serious side effects while using Rebif, 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:

  • thrombotic microangiopathy (a rare condition characterized by blood clots in your blood vessels), which may include symptoms such as:
    • fatigue
    • lightheadedness
    • confusion
    • seizures
    • shortness of breath
  • seizures, which may include symptoms such as:
    • falling to the ground
    • twitching
    • jerking movements
    • loss of consciousness
    • repeated blinking
  • changes in blood cell levels, such as decreased levels of white blood cells, red blood cells, and platelets. Symptoms may include:
    • unexplained bruising or bleeding
    • increased risk of infection
    • tiredness
    • shortness of breath
  • severe liver problems, which may include symptoms such as:
    • loss of appetite
    • fatigue
    • nausea or vomiting
    • pain in the upper right side of the abdomen
    • unexplained weight loss
    • jaundice
  • pulmonary arterial hypertension (high blood pressure in the lungs), which may include symptoms such as:
    • fatigue
    • shortness of breath
    • weakness
    • chest pain
  • depression or suicidal thoughts or behaviors*

In rare cases, Rebif may lead to new autoimmune conditions, such as thyroid problems or lupus-like syndrome. Your doctor may perform tests if you show symptoms like joint pain, rashes, or unusual swelling. Talk with your doctor if you experience any of these side effects.

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

ALLERGIC REACTION

For some people, Rebif 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 Rebif, your doctor may recommend taking a different medication instead.

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

How do side effects of Rebif compare with those seen with Copaxone?

Rebif and Copaxone are both approved by the Food and Drug Administration (FDA) to treat certain forms of multiple sclerosis (MS) in adults. However, the active ingredient of each medication is different. (An active ingredient is what makes a drug work.) Rebif contains interferon beta-1a, while Copaxone contains glatiramer acetate. So, the side effects of these drugs may be different.

To learn more about the side effects of Rebif and Copaxone, talk with your doctor. You can also refer to this article for more details about Copaxone’s side effects.

Does Rebif cause long-term side effects?

Yes, in some cases, Rebif may cause long-term side effects. These can last for a while after you’ve stopped using the drug.

Examples of long-term side effects reported with Rebif include:

Talk with your doctor to learn more about these side effects and how to manage them. Ask your doctor for more information about how long these side effects of Rebif may last.

Can Rebif cause cancer?

It’s not likely. Cancer was not reported as a side effect in clinical trials of Rebif. However, that doesn’t mean cancer cannot occur or won’t be reported in the future.

If you have concerns about cancer as a side effect of Rebif, talk with your doctor.

Learn more about some of the side effects that Rebif may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Rebif.

Injection site reactions

In studies, injection site reactions were common in people using Rebif. These included pain and necrosis (death of your skin cells). Some cases of necrosis can require treatment with antibiotics or surgery.

In rare cases, Rebif may also cause redness or discoloration, swelling, cellulitis (a type of infection), and abscess (a pocket of pus). But it’s important to note that these injection site reactions weren’t seen during studies of Rebif. There have been reports of these side effects in people using Rebif, but it’s unclear how often this has happened or if Rebif was the cause.

What you can do

To lower the risk of injection site reactions, it’s important that you administer the medication carefully according to the instructions for use. Other tips include:

  • washing your hands thoroughly before giving the injection
  • cleaning the injection site before giving yourself a dose
  • rotating injection sites each time you give yourself an injection
  • only using a Rebif syringe or autoinjector once and discarding any unused portions after each use

If you develop any breakage in your skin, swelling, fluid drainage, or black-blue discoloration at the injection site, contact your doctor right away.

Depression

Rebif can increase your risk of depression, suicide attempts, and suicidal thoughts and behaviors. If you have a history of depression, your risk of these side effects may be higher.

Symptoms may include:

  • loss of interest or pleasure in hobbies
  • decreased energy or fatigue
  • changes in sleep patterns
  • difficulty concentrating
  • changes in appetite
  • feelings of guilt or worthlessness

What you can do

If you develop any symptoms of depression, contact your doctor right away. If needed, they can refer you to a mental health specialist for help. They can also help determine if you should continue Rebif treatment. If you have thoughts of harming yourself, call 911 or your local emergency number right away.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

Below is important information you should consider before using Rebif.

Precautions

Before using Rebif, discuss your health history with your doctor. Rebif 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:

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.