Interferon Beta-1a (Intramuscular route, subcutaneous route)
Interferon, Beta (class)
Uses of This Medicine:
Interferon beta-1a injection is used to treat the relapsing forms of multiple sclerosis (MS). This medicine will not cure MS, but it may slow some disabling effects and decrease the number of relapses of the disease. Interferons are natural substances that are produced in the body to help fight infections. Interferon beta-1a is a synthetic (man-made) version of these substances.
This medicine is available only with your doctor's prescription.
Before Using This Medicine:
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of interferon beta-1a injection in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of interferon beta-1a injection in the elderly. However, elderly patients are more likely to have age-related liver problems, which may require caution in patients receiving interferon beta-1a injection.
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems—
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
Proper Use of This Medicine:
A nurse or other trained health professional will give you this medicine. You may also be taught how to give your medicine at home. This medicine is given as a shot under your skin or into a muscle.
If you are injecting interferon beta-1a yourself, use it exactly as directed by your doctor. Do not use more or less of it, and do not use it more often than your doctor ordered. Do not change your dose or dosing schedule without checking first with your doctor. The exact amount of medicine you need has been carefully worked out. Using too much will increase the risk of side effects, while using too little may not improve your condition.
You will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas.
Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.
Rebif® works best if you use it on the same time (usually in the late afternoon or evening) on the same three days (e.g., Monday, Wednesday, and Friday) at least 48 hours apart each week.
Avonex® comes as a prefilled syringe or a powder. The powder must be mixed with sterile water before it is given. Do not shake the vial after you add the water. Gently swirl the water and medicine together to mix. The mixture should be clear or slightly yellow. Do not use the mixture if you see particles in it. Use the medicine as soon as possible after mixing. If you cannot give your shot right away, you can keep the syringe in the refrigerator for up to 6 hours. After 6 hours, throw the medicine away and mix another dose.
Use a new needle, unopened vial, or syringe each time you inject your medicine.
Each package of interferon beta-1a injection contains a medication guide and patient instruction sheet. Read this sheet carefully and make sure you understand:
If you have any questions about any of this, check with your doctor.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
If you miss a dose or forget to use your medicine, use it as soon as you can. This will then change the time for your next dose. After using the missed dose, use your next regular dose of Rebif® 48 hours later and go back to your regular schedule the following week. For Avonex®, if your next regular dose is less than 2 days away, call your doctor. For either brand, do not use extra medicine to make up for a missed dose and do not use this medicine two days in a row.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Store prefilled syringes or vials in the refrigerator. Do not freeze. If refrigeration is not available, Rebif® prefilled syringes and Avonex® powder vials may be kept for up to 30 days at room temperature, away from heat (temperatures above 77 degrees F) and direct light. Avonex® prefilled syringes may be stored for up to 7 days at room temperature, away from heat (temperatures above 77 degrees F) and direct light. Allow Avonex® prefilled syringes to warm to room temperature (remove from the refrigerator for about 30 minutes) before injection but do not heat in a microwave oven or in hot water.
Throw the used needles away in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.
Precautions While Using This Medicine:
It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.
Using this medicine while you are pregnant may cause you to lose your baby or can harm your unborn baby. Tell your doctor right away if you think you are pregnant or if you plan to become pregnant while using this medicine. Also, tell your doctor if you are breastfeeding.
This medicine may cause some people to be anxious, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you or your caregiver notice any of these side effects, tell your doctor right away.
Check with your doctor right away if you have dark urine, persistent loss of appetite, influenza (flu)-like symptoms, headache, continuing vomiting, general feeling of tiredness or weakness, light-colored stools, right upper stomach pain or tenderness, or yellow eyes or skin. These could be symptoms of a serious liver problem.
You should avoid alcohol while you are taking this medicine. It can cause serious liver problems.
This medicine may cause serious allergic reactions including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash; itching; hoarseness; trouble breathing; trouble swallowing; or any swelling of your hands, face, or mouth while you are using this medicine.
This medicine may lower the number of white blood cells in the blood. This will increase your chance of getting an infection. It can also lower the number of platelets in the blood. Platelets are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:
This medicine may cause redness, pain, or swelling at the injection site. Some patients have developed skin infections or a permanent depression (necrosis) under the skin at the injection site. Contact your doctor right away if you notice any of these side effects at the injection site: depressed or indented skin; blue-green to black skin discoloration; or pain, redness, or sloughing (peeling) of the skin.
This medicine commonly causes a flu-like reaction, with aching muscles, chills, fever, headache, joint pain, and nausea. Using your shot at bedtime may allow you to sleep through the symptoms. Your doctor may want you to take a medicine for pain and fever (e.g., acetaminophen or ibuprofen) to help control these effects. Follow your doctor's instructions carefully about how to prevent or treat these symptoms.
This medicine contains albumin, which comes from human blood. Some human blood products have transmitted certain viruses to people who have received them. The risk of getting a virus from medicines made of human blood has been greatly reduced in recent years. This is the result of required testing of human donors for certain viruses, and testing during manufacture of these medicines. Although the risk is low, talk with your doctor if you have concerns. The Avonex® prefilled syringe does not contain albumin which comes from donated human blood.
Side Effects of This Medicine:
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Last Updated: 11/4/2010
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