Interferon is a substance that is made naturally by our body's cells to fight infections and tumours. Man-made or synthetic versions of interferon have been made to target specific types of unwanted cells.

Interferon alfa-2b belongs to a group of medications called biological response modifiers. It is used to treat different types of leukemia (a cancer of the blood), malignant melanoma (a skin cancer), basal cell carcinoma (a skin cancer), multiple myeloma (a cancer of the blood), non-Hodgkin's lymphoma (a cancer of the lymph cells), and AIDS-related sarcoma.

Interferon alfa-2b is also used to treat certain types of hepatitis (a disease of the liver) and is also used to treat some cases of genital warts.

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 taking this medication, speak to your doctor. Do not stop taking 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 take this medication if their doctor has not prescribed it.

The recommended dose and dosing schedule of interferon alfa-2b varies according to the specific condition being treated, the response to therapy, the side effects experienced, and the other medications or treatments being used. The dose administered is also based on body size. It is usually injected under the skin (subcutaneous or SC) or into a muscle (intramuscular or IM).

If you are giving yourself injections, it is very important that you carefully follow the doctor's instructions and the instructions included with the medication. Your doctor or nurse will assist you in the preparation and injection of your first dose (or first few doses). Do not attempt to inject this medication on your own until you completely understand how to inject a dose.

Do not change the way that you are using the medication without consulting your doctor.

It is important to use this medication exactly as prescribed by your doctor. If you miss a dose of this medication, use it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. 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.

Store this medication in the refrigerator at 2°C to 8°C, do not allow it to freeze, and keep it out of the reach of children.

If necessary, the powder form of this medication can be kept at room temperature (up to 25°C) for up to 4 weeks before using. After 4 weeks, it cannot be put back in the refrigerator for a new storage period and should be discarded.

If the powder form is mixed with bacteriostatic water for injection (preserved with benzyl alcohol), it can be stored in the refrigerator (2°C to 8°C) for up to 30 days or at room temperature (15°C to 30°C) for up to 14 days. After these time periods, discard any unused portion. If the powder form of this medication is mixed with sterile water for injection, it should be used as soon as possible within 3 hours.

The 10M unit vial solution for injection should be stored in the refrigerator at 2°C to 8°C for up to 7 days after the first use.

The 18M unit and 25M unit solution vials should be stored in the refrigerator at 2°C to 8°C for up to 4 weeks after the first use. The vials can be stored at room temperature (up to 25°C) for a period of 7 days before use and can be put back in the refrigerator at any time during this 7-day period. If the product is not used during the 7-day period, it cannot be put back in the refrigerator for a new storage period and should be discarded.

The multi-dose pens should be stored in the refrigerator at 2°C to 8°C. Each pen is intended for a maximum 4-week use period and then must be discarded. A new needle must be used for each dose. After each use, the needle should be discarded safely, and the pen must be returned to the refrigerator immediately. If the pen is accidentally left at temperature (15°C to 25°C), a maximum total of 48 hours (2 days) of exposure at room temperature is allowed over the 4-week use period.

Do not use this medication if you:

• are allergic to interferon or any ingredients of this medication
• have autoimmune hepatitis (hepatitis caused by your immune system attacking your liver)
• have severely reduced kidney function and are taking ribavirin
• have unstable liver disease

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is used 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 using 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.

• appetite loss
• back pain
• constipation
• diarrhea
• flu-like symptoms (e.g., fever, chills, headache, fatigue, muscle and joint aches) that usually decrease after 1 or 2 weeks
• irritability
• loss of appetite
• muscle or joint pain
• nausea
• pain, stinging, redness, burning at the place of injection
• sleeping problems
• taste changes
• temporary hair loss
• vomiting
• weight loss

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

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

• aggressive behaviour or other behaviour changes
• agitation
• anxiety
• blurred vision or vision changes
• confusion
• diarrhea or constipation
• dizziness
• fever or chills (starting 3 weeks after beginning of treatment)
• hallucinations (hearing, seeing or feeling things that aren't there)
• irregular or fast heartbeat
• irritability
• loss of hearing
• muscle or joint pain
• nausea
• nervousness
• numbness or tingling of fingers, toes and face
• persistent and severe cough or shortness of breath
• sore throat and painful swallowing
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood,  bleeding gums, cuts that don’t stop bleeding)
• symptoms of depression (e.g., loss of interest in usual activities, feeling sad or hopeless, difficulty concentrating, increased or decreased appetite, increased sleep or difficulty sleeping)
• symptoms of high blood glucose (sugar) such as excessive thirst or urination and increased hunger
• symptoms of hypothyroidism (e.g., dry skin, constipation, weight gain, fatigue, aches, pains and stiffness, intolerance to cold, depression, memory problems)
• symptoms of liver problems (e.g., yellowing of the eyes or skin, nausea, vomiting, abdominal pain, pale stools, dark urine)
• symptoms of low red blood cells (e.g., fast heartbeat, shortness of breath, paleness, tiredness)
• symptoms of sarcoidosis (e.g., fever, weight loss, joint pain and swelling, skin lesions and swollen glands)
• trouble thinking or concentrating
• vomiting

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

• loss of consciousness
• muscle pain or weakness, especially if accompanied by dark urine
• seizures
• severe skin rash (e.g., peeling skin or blistering skin)
• signs of bleeding in the stomach (e.g., bloody, black, or  tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
• symptoms of a heart attack (e.g., chest pain or pressure that may move to the back or jaw, anxiety, sweating, nausea, difficulty breathing)
• symptoms of a severe allergic reaction (e.g., hives; difficulty breathing; difficulty swallowing; fainting; swelling of the hands, feet, face, mouth, throat, or tongue)
• symptoms of a stroke (e.g., sudden and severe headache, sudden weakness or numbness in the arms or legs, sudden vision changes, sudden dizziness, or sudden difficulty talking or walking)
• symptoms of inflammation of the pancreas (e.g., severe abdominal pain with or without vomiting)
• thoughts of suicide or harming yourself

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.

Autoimmune conditions: This medication may cause or worsen autoimmune conditions (e.g., thyroiditis, systemic lupus erythematosus). If you develop any new or worsening symptoms while using this medication, contact your doctor.

Blood glucose (sugar): This medication can cause high blood sugar. If you have diabetes, 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 symptoms of high blood sugar (increased thirst, hunger, weakness, drowsiness, blurred vision, weight loss) while taking this medication, contact your doctor.

Colon disorders: This medication may cause certain types of colitis. Report any stomach or abdominal pain, bloody diarrhea, or fever to your doctor immediately.

Depression and other mental health disorders: If you have or have had depression or any other mental health issue (e.g., schizophrenia, obsessive compulsive disorder, substance abuse), your doctor should closely monitor your condition while you are using this medication. If you develop severe depression or experience other mood or behaviour changes, stop using this medication and contact your doctor immediately. If you have thoughts or feelings about harming yourself, get immediate medical attention.

Dental health: If you are taking ribavirin and are using this medication, you may be more likely to have dental health issues. It is important to brush your teeth thoroughly twice a day and have regular dental exams if you are taking ribavirin and this medication. If you vomit, rinse your mouth out thoroughly to reduce damage to teeth.

Diabetes: This medication can cause changes in blood sugar levels. If you have diabetes, 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 required.

Drowsiness, fatigue or confusion: Since this medication can cause side effects such as drowsiness, fatigue and confusion, you should not drive or operate machinery until you know that this medication does not affect your ability to do these activities safely.

Eye disorders: Certain eye disorders have been observed in people using this medication. You should have an eye examination before starting this medication and periodically during treatment. If you experience any changes in vision (e.g., vision loss, blurred vision) while using this medication, contact your doctor.

Fever and flu-like symptoms: This medication can cause fever and other flu-like symptoms such as chills and headache. If you have heart disease (e.g., unstable angina, uncontrolled heart failure), lung disease (e.g., chronic bronchitis, emphysema) or have unstable diabetes, 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 may suggest that you take acetaminophen if you develop these symptoms.

If you have a persistent fever while using this medication, contact your doctor.

Heart disease: Interferon alfa-2b can cause chest pain, high blood pressure, an abnormal heart rhythm, or a heart attack. If you have severe heart disease, or have had severe heart disease in the last 6 months, you should not use this medication.

If you have heart disease (e.g., heart failure, heart attack, or an abnormal heart rhythm) or have AIDS-related sarcoma, 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 symptoms of heart problems such as chest pain, an abnormal heart rhythm, shortness of breath, dizziness or fainting while using this medication, contact your doctor immediately or get immediate medical attention.

Infection: This medication can reduce the number of cells that fight infection in the body (white blood cells). Your doctor will monitor your white blood cell counts while you are using this medication, especially if your immune system is suppressed (e.g., if you have an immune system problem or are taking medication that suppresses the immune system). Avoid contact with people with contagious infections and tell your doctor if you begin to notice signs of an infection, such as fever or chills.

Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney 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.

If you have severely reduced kidney function, your doctor will regularly monitor your kidney function with blood tests.

Liver disorders: This medication may affect your liver function. If you have chronic hepatitis B, 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 unstable liver disease, you should not use this medication.

Lung inflammation: Lung inflammation (interstitial lung disease), causing difficulty breathing has occurred rarely in some people taking this medication. This complication can be serious and sometimes fatal. If you experience new or worsening shortness of breath or cough (with or without fever) at any time while you are taking interferon alfa-2B contact your doctor immediately.

Pancreatitis (inflammation of the pancreas): This medication can cause pancreatitis, which may be fatal. If you develop symptoms of pancreatitis (e.g., severe abdominal with or without vomiting), get immediate medical attention.

Skin problems: This medication may worsen psoriasis or sarcoidosis. If you have these conditions, 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.

Stroke: This medication has been associated with strokes. If you experience symptoms of a stroke (e.g., sudden and severe headache, sudden weakness or numbness in the arms or legs, sudden vision changes, sudden dizziness, or sudden difficulty talking or walking), get immediate medical attention.

Thyroid disorders: This medication can cause or worsen hypothyroidism (low thyroid) or hyperthyroidism (high thyroid). If you have a thyroid condition, 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.

Transplants: The safety and effectiveness of using this medication have not been established for people who have had a liver or other organ transplant.

Triglycerides: This medication may increase the triglyceride (a type of fat) levels in your blood. Your doctor will monitor for this with blood tests.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while using this medication, contact your doctor immediately. If you may become pregnant, you should use an effective method of birth control while you are using this medication.

Breast-feeding: It is not known if interferon alfa-2b passes into breast milk. If you are a breast-feeding mother and are using 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 alfa-2b and any of the following:

• anticancer medications (e.g., methotrexate, doxorubicin, vincristine)
• BCG
• clozapine
• dipyrone
• methadone
• ribavirin
• telbivudine
• theophyllines (e.g., aminophylline, oxtryphylline, theophylline)
• tizanidine
• 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.