What are the long term side effects of Rebif?

Rebif (interferon beta-1a) is an effective medication for relapsing forms of multiple sclerosis (MS), but it has a few potential long-term side effects. Data from over two decades of clinical experience and studies have shown that most side effects of Rebif are temporary and reversible. More rare but long-term side effects may include liver damage, lung damage, and skin damage at the injection site.

Regular follow-up appointments with your healthcare provider can help manage potential side effects. They might need to order blood tests to check the health of your organs and monitor your blood cell count.

Liver damage

Although rare, Rebif can cause liver damage. Your risk might be higher if you drink excessive amounts of alcohol, take other medications that can harm the liver, or have a history of liver problems. You might not notice any symptoms from liver damage, and most cases are mild. However, some patients have experienced liver failure and have required a liver transplant.

Symptoms of liver damage usually start after 1-6 months of starting treatment with Rebif. Signs of liver damage may include:

• Yellowing of the skin or whites of the eyes
• Nausea and/or vomiting
• Stomach pain
• Clay-colored stool

Contact your healthcare provider right away if you notice any of the symptoms listed above. They can check your liver health to make sure you do not have any liver problems. Your healthcare provider may need to temporarily lower your dose or stop your treatment with Rebif if necessary.

Lung damage

Some patients taking Rebif developed pulmonary arterial hypertension (PAH), a condition characterized by high blood pressure in the lungs. This has led to lung damage and even a lung transplant in one patient. PAH can occur anytime during treatment. Some patients have experienced PAH several years after starting Rebif.

Symptoms of PAH may include:

• Shortness of breath
• Feeling more tired than usual
• Cough
• Chest pain
• Swelling in the feet or legs
• Hoarse voice

Get medical attention if you have any of the symptoms listed above.

Related questions

• How effective is Rebif for MS?
• How and where do you inject Rebif?
• What is Rebif used for and how does it work?

Skin damage at the injection site

Rebif is given as an injection under the skin three times a week. Injection-site reactions are a common side effect of Rebif, and may include redness, pain, and swelling. However, some patients rarely experience severe skin damage, including necrosis. This is when the skin dies near the area where Rebif is injected. Some patients have needed to get surgery to repair the skin damage.

To prevent severe injection-site reactions, such as necrosis, make sure to rotate injection sites with each dose of Rebif. Tell your healthcare provider if you notice a severe reaction where you have injected the medication.

Damage to other organs in the body

Thrombotic microangiopathy has occurred rarely in patients taking Rebif. It can lead to blood clots in your blood vessels, which can cause damage to organs such as your kidneys. This can happen weeks to years after starting Rebif.

This is not all the information you need to know about Rebif (interferon beta-1a) for safe and effective use and does not take the place of your healthcare provider’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.