Interferon beta-1a Subcutaneous Injection (patient information)

# Why this medication is prescribed
Interferon beta-1a is used to prevent episodes of symptoms and slow the development of disability in patients with relapsing-remitting multiple sclerosis (MS, a disease in which the nerves do not function properly and patients may experience weakness, numbness, loss of muscle coordination and problems with vision, speech, and bladder control). Interferon beta-1a has not been shown to help patients with chronic progressive MS. Interferon beta-1a is in a class of medications called immunomodulators. It is not known how interferon beta-1a works to treat MS.

# How this medication should be used
Interferon beta-1a subcutaneous injection comes as a solution to inject subcutaneously (under the skin) three times a week. You should inject this medication on the same 3 days every week, for example, every Monday, Wednesday, and Friday. The injections should be spaced at least 48 hours apart, so it is best to inject your medication around the same time of day on each of your injection days. The best time to inject this medication is in the late afternoon or evening. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Use interferon beta-1a exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor.
Your doctor may start you on a low dose of interferon beta-1a and gradually increase your dose, not more than once every 2 weeks.
Interferon beta-1a controls symptoms of MS, but does not cure it. Continue to take interferon beta-1a even if you feel well. Do not stop taking interferon beta-1a without talking to your doctor.
You will receive your first dose of interferon beta-1a in your doctor's office. After that, you can inject interferon beta-1a yourself or have a friend or relative perform the injections. Before you use interferon beta-1a yourself the first time, read the written instructions that come with it. Ask your doctor or pharmacist to show you or the person who will be injecting the medication how to inject it.
Interferon beta-1a comes in prefilled syringes. Use each syringe and needle only once and inject all the solution in the syringe. Even if there is still some solution left in the syringe after you inject, do not inject again. Throw away used syringes and needles in a puncture-resistant container kept out of reach of children. Talk to your doctor or pharmacist about how to throw away the puncture-resistant container.
You can inject interferon beta-1a in areas of your body with a layer of fat between the skin and muscle, such as your thigh, the outer surface of your upper arms, your stomach, or your buttocks. If you are very thin, only inject in your thigh or the outer surface of your arm for injection. Use a different spot for each injection. Keep a record of the date and spot of each injection. Do not use the same spot two times in a row. Do not inject near your navel (belly button) or waistline or into an area where the skin is sore, red, bruised, scarred, infected, or abnormal in any way.
To inject interferon beta-1a, follow these steps:
- Remove the prefilled syringe from the refrigerator and allow it to warm to room temperature for about 30 minutes before using. Do not use a heat source such as hot water or a microwave to warm the syringe.
- Check the syringe to be sure it is safe to use. The syringe should be labeled with the correct name of the medication and an expiration date that has not passed and should contain a clear to slightly yellow solution. If the syringe is expired, or the solution is cloudy, discolored, or contains particles, do not use it and call your pharmacist.
- Set-up a clean, well-lit, flat work surface, like a table, to collect all the supplies you will need to inject interferon beta-1a. Assemble these supplies: alcohol wipes, gauze pad, small adhesive bandage, and puncture-resistant container for disposal of used syringes and needles.
- Wash your hands well with antibacterial soap.
- Choose a spot to inject interferon beta-1a and clean it with an alcohol wipe, using a circular motion. Let the skin air dry.
- Remove the cap from the syringe needle.
- The syringe should be filled with interferon beta-1a to the 0.5 mL mark. This is a full dose. #If your doctor has told you to use less than the full dose, slowly push the syringe plunger in until the amount of medication left in the syringe is the amount your doctor told you to use.
- Use your thumb and forefinger to pinch up a pad of skin around the spot where you will inject interferon beta-1a. Hold the syringe like a pencil with your other hand.
- Hold the syringe at a 90-degree angle (straight up and down), and push the needle straight into your skin, stopping just underneath the skin.
- When the needle is in, let go of the pinched skin and slowly push down on the syringe plunger until the syringe is empty.
- Hold a gauze pad near the needle and pull the needle straight out of the skin. Use the gauze pad to apply pressure to the spot for a few seconds. You may cover the spot with a bandage.
- Throw away the used syringe, needle, and gauze pad properly.
- Apply a cold compress or ice pack to the injection spot to help reduce redness, swelling, or tenderness that may occur.
- After 2 hours, check the injection spot for redness, swelling, or tenderness. If you have redness, swelling, or tenderness that does not go away in a few days or is severe, call your doctor.

# Other uses for this medicine
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

# Special precautions
Before using interferon beta-1a:
- tell your doctor and pharmacist if you are allergic to interferon beta-1a, any other interferon product, any other medications, or human albumin.
- tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: acetaminophen (Tylenol, others); antidepressants; azathioprine (Imuran); cancer chemotherapy medications; carbamazepine (Tegretol); chloramphenicol (Chloromycetin); cholesterol-lowering medications (statins); cyclosporine (Neoral, Sandimmune); gold compounds such as auranofin (Ridaura) and aurothioglucose (Solganol); heparin; iron products; isoniazid (INH, Nydrazid); medications for acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV); methotrexate (Rheumatrex); niacin (nicotinic acid); penicillamine (Cuprimine, Depen); phenytoin (Dilantin, Phenytek); rifampin (Rifadin, Rimactane); sirolimus (Rapamune); sulfa antibiotics such as sulfamethoxazole (Bactrim, Septra) and sulfisoxazole (Gantrisin); thyroid medications; and tacrolimus (Prograf). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you drink or have ever drunk large amounts of alcohol and if you have or have ever had AIDS or HIV; an autoimmune disease (a disease in which the body attacks its own cells; ask your doctor if you are not sure if you have this type of disease); blood problems such as anemia (low red blood cells) or easy bruising or bleeding; anxiety, depression, or mental illness; cancer; seizures; or kidney, liver, or thyroid disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking interferon beta-1a, call your doctor immediately.
- if you are having surgery, including dental surgery, tell the doctor or dentist you are using interferon beta-1a.
- ask your doctor about the safe use of alcoholic beverages while you are using interferon beta-1a. Alcohol can make the side effects of interferon beta-1a worse.
- you should know that you may have flu-like symptoms such as headache, fever, chills, sweating, muscle aches, back pain, and tiredness that last for a day after your injection. Your doctor may tell you to take an over-the-counter pain and fever medication to help with these symptoms. *These symptoms usually improve or go away over time. Talk to your doctor if these symptoms last longer than the first few months of therapy, or if they are difficult to manage or become severe.

# Special dietary instructions
Unless your doctor tells you otherwise, continue your normal diet.

# What to do if you forget a dose
Inject the missed dose as soon as you remember it. If you are scheduled for a dose the following day, skip that dose. Do not inject interferon beta-1a 2 days in a row. Do not inject a double dose to make up for a missed dose. You should return to your regular dosing schedule the following week. Call your doctor if you miss a dose and have questions about what to do.

# Side effects

## Minor side effects
Interferon beta-1a may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- dry eyes
- dry mouth
- upset stomach
- vomiting
- stomach pain
- tight muscles
- bruising, pain, redness, swelling, or tenderness in the place where you injected interferon *beta-1a

## Severe side effects
Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:
- depression
- thoughts of hurting yourself or others
- anxiety
- hives
- skin rash
- itching
- flushing
- difficulty breathing or swallowing
- lightheadedness
- fainting
- seizures
- loss of coordination
- vision problems
- extreme tiredness
- lack of energy
- loss of appetite
- pain in the upper right part of the stomach
- yellowing of the skin or eyes
- pale skin
- chest pain
- fast heartbeat
- difficulty sleeping
- unusual bruising or bleeding
- swollen glands in your neck
- sore throat, cough, fever, chills, or other signs of infection
- unexplained weight gain or loss
- feeling cold or hot all the time
- blackening of skin or drainage in the place where you injected interferon beta-1a
Interferon beta-1a may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online  or by phone .

# Storage conditions needed for this medication
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it in the refrigerator, but do not freeze it. If a refrigerator is not available, you can store the medication at room temperature away from heat and light for up to 30 days. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

# In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

# Other information
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to interferon beta-1a.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

# Brand names
- Rebif