What is interferon beta-1a?

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.

Precautions

Do not use this medication if you are allergic to interferons or human albumin.

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.

Before using interferon beta-1a, tell your doctor if you are allergic to any drugs, or if you have:

  • liver disease;
  • epilepsy or other seizure disorder;
  • heart disease, chest pain (angina), congestive heart failure, or a heart rhythm disorder;
  • a thyroid disorder; or
  • a history of depression or suicidal behavior.

If you have any of these conditions, you may need a dose adjustment or special tests to safely use interferon beta-1a.

FDA pregnancy category C. 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 become pregnant during treatment.

It is not known whether interferon beta-1a passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Interferon beta-1a is made from human plasma (part of the blood) and may contain viruses and other infectious agents that can cause disease. Although donated human plasma is screened, tested, and treated to reduce the risk of it containing anything that could cause disease, there is still a small possibility it could transmit disease. Talk with your doctor about the risks and benefits of using this medication.

Avoid drinking alcohol while using interferon beta-1a. Alcohol may increase your risk of liver damage.

Interferons can lower the blood cells that help your body fight infections. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Avoid being near people who have colds, the flu, or other contagious illnesses. Contact your doctor at once if you develop signs of infection.

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Instructions

Seek emergency medical attention if you think you have used too much of this medicine. Symptoms of an interferon beta-1a overdose are not known.

Call your doctor for instructions if you miss a dose of this medication.

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Side Effects

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. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

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Interactions

Interferon beta-1a can be harmful to your liver, and these effects are increased when interferon beta-1a is used together with other medicines that can harm the liver. Before using this medication, tell your doctor if you are also using:

  • acetaminophen (Tylenol);
  • cancer medications;
  • tuberculosis medications;
  • birth control pills or hormone replacement therapy;
  • methotrexate (Rheumatrex, Trexall);
  • arthritis medications such as auranofin (Ridaura) or aurothioglucose (Solganol);
  • an antibiotic;
  • HIV/AIDS medications;
  • cholesterol medications such atorvastatin (Lipitor), simvastatin (Zocor), and others;
  • an ACE inhibitor such as benazepril (Lotensin), captopril (Capoten), lisinopril (Prinivil, Zestril), and others;
  • an NSAID (non-steroidal anti-inflammatory drug) such as ibuprofen (Motrin, Advil), naproxen (Aleve, Naprosyn), indomethacin (Indocin), and others; or
  • seizure medications such as carbamazepine (Carbatrol, Tegretol), phenytoin (Dilantin), or valproic acid (Depakene).

This list is not complete and there may be other drugs that can interact with interferon beta-1a. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Other Names

Avonex, Avonex Prefilled Syringe, Rebif, and interferon beta-1a

Available Strengths & Dosages


Route Form Strength
intramuscular powder for injection 30 mcg

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Disclaimer

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04

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