Generic Name: interferon beta-1a (in ter FEAR on BAY ta)Brand Names: 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.
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 and liver function will need to be tested on a regular basis. Your thyroid function may also need to be tested. Do not miss any scheduled appointments.
If you have any of these other conditions, you may need a dose adjustment or special tests to safely use interferon beta-1a:
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.
Avonex powder contains albumin, but the Avonex prefilled syringe does not. Albumin comes 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.
Interferon beta-1a is given as an injection under the skin or into a muscle. Your doctor, nurse, or other healthcare provider will give you this injection. You may be shown how to inject your medicine at home.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.
Interferon beta-1a is injected into a muscle of the thigh or upper arm. This medication comes with patient instructions for safe and effective use. Follow these directions carefully. Ask your doctor or pharmacist if you have any questions.
The powder form of interferon beta-1a must be mixed with a liquid (diluent) in the medicine vial. Gently swirl but do not shake the vial after mixing the medicine. The mixture should be clear or light yellow. Do not use the mixture if it has changed colors or has any particles in it. Mix a new dose or call your doctor for a new prescription.Do not draw your interferon beta-1a dose into a syringe until you are ready to give yourself an injection.
Use each disposable needle only one time. Throw away used needles in a puncture-proof container (ask your pharmacist where you can get one and how to dispose of it). Keep this container out of the reach of children and pets.
To be sure this medication is not causing harmful effects, your blood and liver function will need to be tested on a regular basis. Your thyroid function may also need to be tested. Do not miss any scheduled visits to your doctor.Store interferon beta-1a in a refrigerator. Do not freeze. You may take the prefilled syringe out of the refrigerator and allow it to reach room temperature before giving the injection. Do not heat the medicine before using. Interferon beta-1a may be kept at room temperature for short periods if protected from light. Powder medication can be stored at room temperature for up to 30 days. The Rebif prefilled syringe can also be stored at room temperature for up to 30 days. However, the Avonex prefilled syringe can be stored at room temperature for only 7 days.
Interferon beta-1a mixed with the diluent may be stored in a refrigerator, but you must use it within 6 hours after mixing.
Throw away any interferon beta-1a that has become frozen or has been exposed to light or high heat.
Call your doctor for instructions if you miss a dose of this medication.
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.
depressed mood, anxiety, trouble sleeping, restlessness, or thoughts of suicide or hurting yourself;
easy bruising or bleeding, weakness;
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:
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.
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:
birth control pills or hormone replacement therapy;
methotrexate (Rheumatrex, Trexall);
arthritis medications such as auranofin (Ridaura);
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.