Medications and Drugs

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Brand Names: Avonex, Avonex Prefilled Syringe, Rebif

Generic Name: interferon beta-1a (Pronunciation: in ter FEAR on BAY ta)

• What is interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?
• What are the possible side effects of interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?
• What is the most important information I should know about interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?
• What should I discuss with my healthcare provider before using interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?
• How should I use interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?
• What happens if I miss a dose (Avonex, Avonex Prefilled Syringe, Rebif)?
• What happens if I overdose (Avonex, Avonex Prefilled Syringe, Rebif)?
• What should I avoid while using interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?
• What other drugs will affect interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?
• Where can I get more information?

What is interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?

Interferon beta-1a is made from human proteins. Interferons help the body fight viral infections.

Interferon beta-1a is used to treat relapsing multiple sclerosis (MS). This medication will not cure MS, it will only decrease the frequency of relapse symptoms.

Interferon beta-1a may also be used for other purposes not listed in this medication guide.

What are the possible side effects of interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

• depressed mood, anxiety, trouble sleeping, restlessness, or thoughts of suicide or hurting yourself;
• easy bruising or bleeding, weakness;
• seizure (convulsions);
• numbness or tingling in your hands or feet;
• pain or burning when you urinate;
• pain, swelling, or skin changes where the injection was given;
• fever, chills, body aches, flu symptoms; or
• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

• headache, dizziness;
• stomach pain; or
• runny or stuffy nose.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about interferon beta-1a (Avonex, Avonex Prefilled Syringe, Rebif)?

This medication may be harmful to an unborn baby, or may cause a miscarriage. Do not use interferon beta-1a if you are pregnant. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Before using interferon beta-1a, tell your doctor if you are allergic to any drugs, or if you have liver disease, a thyroid disorder, epilepsy or other seizure disorder, heart disease, chest pain (angina), congestive heart failure, a heart rhythm disorder, or a history of depression or suicidal behavior.

Some patients using interferon medications have become very depressed or had thoughts of suicide. Stop using interferon beta-1a if you have symptoms of depression (sadness, crying, loss of interest in things you once liked) or if you have any thoughts of hurting yourself.

Do not self-inject this medicine if you do not fully understand how to give the injection and properly dispose of used needles and syringes.

To be sure this medication is not causing harmful effects, your blood may need to be tested often. Your liver or thyroid function may also need to be tested. Visit your doctor regularly.

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