Interferon beta-1b belongs to the group of medications known as immunomodulators. It is a form of a protein that is naturally made by our body's cells to fight infections and tumours. Interferon beta-1b is used to treat relapsing forms of multiple sclerosis (MS).

Multiple sclerosis (MS) is a chronic and disabling disease caused by the body's own defense system attacking and destroying the protective covering known as myelin that surrounds the nerves. Interferon beta-1b works by slowing down the attack of the body's defense cells on the nerves. Interferon beta-1b is used to reduce the frequency of exacerbations (worsening of symptoms) for people suffering with relapsing-remitting multiple sclerosis.

This medication is also used to delay the onset of MS for people who have experienced a single flare-up of symptoms and have changes that suggest MS in their magnetic resonance imaging (MRI) scans.

This medication can also be used to treat people with another type of MS known as SPMS (secondary progressive MS) who are still having relapses. For people with SPMS, the medication can decrease the frequency of relapses and reduce brain lesions seen on MRI scans.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are being given this medication, speak to your doctor. Do not stop using this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to use this medication if their doctor has not prescribed it.

The recommended adult dose of interferon beta-1b is 0.25 mg (8 MIU) injected subcutaneously (under the skin) every other day. In some cases, the doctor may prescribe a lower dose to start, and gradually increase the dose until the recommended adult dose has been reached.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are using the medication without consulting your doctor.

Interferon beta-1b is used with the guidance and supervision of a doctor. Your doctor or nurse may ask you to inject the medication at home once they have instructed you and are certain that you won't have any problems with doing it at home. Do not attempt to prepare or inject this medication on your own until you completely understand how to mix and inject a dose.

Use a different injection site for each dose. You should avoid injecting this medication into an area of skin that is sore, red, infected, or otherwise damaged. If you are having difficulty giving yourself injections, talk to your health care provider.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible. Your next injection should be given about 48 hours after the first dose. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

See the package insert for instructions on choosing the injection site, preparing the injection, and injecting the medication. Before mixing, interferon beta-1b should be kept at temperatures between 2°C and 25°C. It can be kept between 25°C and 30°C for a maximum of 30 days. Do not freeze. After mixing, the vial or syringe containing the medication should be kept in a refrigerator and used within 3 hours.

Protect this medication from light, moisture, freezing, and high temperatures. Keep this medication out of reach of children.

Each vial contains 0.3 mg of interferon beta-1b (9.6 MIU). Nonmedicinal ingredients: albumin human USP and mannitol US. Each prefilled diluent syringe contains sodium chloride 0.54%.

Do not use interferon beta-1b if you:

• are allergic to interferon beta-1b or any ingredients of the medication
• are or may be pregnant
• have severe depression or ideas of self harm
• have severe liver disease

Do not give this medication to children and adolescents less than 18 years of age.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• flu-like symptoms (e.g., fever, chills, sweating, muscle aches, tiredness)
• injection site reactions (e.g., skin irritation, swelling, pain, bruising, itching, bleeding)

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• decreased coordination
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of depression (feeling sad, losing interest in things you used to enjoy, weight changes, changes in sleep habits, feelings of guilt or worthlessness, thoughts of suicide)
• signs of heart problems (swollen ankles, shortness of breath, tightness in the chest, decreased ability to exercise, increased heart rate)
• signs of liver problems (yellow eyes or skin, abdominal pain, dark urine or pale stools, easy bruising)
• signs of thyroid problems (weight changes, feeling constantly hot or cold, changes in sleep patterns)
• signs of unusual infections (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, loss of voice, weight loss, or listlessness)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine, change of urine colour)
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• skin rash
• swelling in ankles or legs

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• signs of a serious allergic reaction (e.g., difficulty breathing; hives; swelling of the face, tongue, or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood counts: This medication can decrease the number of neutrophils (a type of white blood cell that helps fight infection) and platelets (which help your blood to clot). Your doctor will do blood tests to monitor this. If you notice any signs of infection (e.g., fever, chills, or sore throat) or unusual bleeding or bruising, contact your doctor immediately.

Depression: Depression has been reported by some people taking interferon medications. If you have a history of depression, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you have depression you should be closely monitored by your doctor. If symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or thoughts of suicide occur while taking this medication contact your doctor as soon as possible. If you notice any of these symptoms in a family member who is taking this medication contact your doctor as soon as possible.

Heart problems: This medication may worsen symptoms of heart disease. If you have heart disease such as angina, congestive heart failure, or arrhythmia, discuss with your doctor how this medication may affect the medical condition, how the medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Contact your doctor as soon as possible if you develop symptoms of heart problems such as shortness of breath, chest pain, rapid heartbeat, or swollen ankles.

Kidney function: Interferon beta 1-b can cause changes to kidney function. If you have decreased kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience puffy hands, face or feet, high blood pressure, unusual muscle cramping, or darkened urine, contact your doctor as soon as possible.

Liver function: This medication may cause severe liver damage. Although rare, this side effect can be very serious. If you have a history of poor liver function, alcohol abuse, or active liver disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Your doctor will test your liver function regularly while you are taking this medication. Contact your doctor as soon as possible if you notice any of the signs of liver damage, including yellow eyes or skin, easy bruising of the skin, nausea and vomiting, itching, or abdominal pain.

Pancreatitis: This medication may cause inflammation of the pancreas (pancreatitis). If you have a history of pancreatitis or are at risk for developing pancreatitis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you develop signs of pancreatitis (e.g., upper left abdominal pain, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen), contact your doctor.

Seizures: Some people have had seizures while taking this medication, including patients who have never had seizures before. It is not known whether the seizures were related to the effects of their MS, to the medication, or to the combination of both. If you have a seizure disorder, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you have a seizure while taking this medication, you should call your doctor right away.

Thyroid problems: Some people taking this medication develop changes in the function of their thyroid. Symptoms of these changes include feeling cold or hot all the time, a change in weight (gain or loss) without a change in your diet or amount of exercise you get, or feeling emotional. Contact your doctor if you experience these symptoms.

Pregnancy: This medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately. Women who may become pregnant should use effective contraception while taking this medication.

Breast-feeding: It is not known if interferon beta-1b passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children and adolescents: The safety and effectiveness of using this medication have not been established for children and adolescents less than 18 years of age.

There may be an interaction between interferon beta-1b and any of the following:

• cladribine
• zidovudine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.