Interferons, Alpha (Systemic)
Interferons, Alpha (Systemic)
US Brand Names
• Alferon N
• Intron A
Canadian Brand Names
• Intron A
Interferons (in-ter-FEER-ons) are substances naturally produced by cells in the body to help fight infections and tumors. They may also be synthetic (man-made) versions of these substances. Alpha interferons are used to treat hairy cell leukemia, malignant melanoma, and AIDS-related Kaposi's sarcoma. They are also used to treat laryngeal papillomatosis (growths in the respiratory tract) in children, genital warts, and some kinds of hepatitis.
Alpha interferons may also be used for other conditions as determined by your doctor.
Alpha interferons are available only with your doctor's prescription, in the following dosage form:
• Interferon Alfa-2a, Recombinant
• Interferon Alfa-2b, Recombinant
• Interferon Alfa-n1 (lns)
• Interferon Alfa-n3
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 interferons, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to alpha interferon or to proteins, such as egg white or immunoglobulin.
Alpha interferons have not been shown to cause birth defects or other problems in humans. However, in monkeys given 20 to 500 times the human dose of recombinant interferon alfa-2a or given 90 to 180 times the usual dose of recombinant interferon alfa-2b, there was an increase in death of the fetuses.
It is not known whether alpha interferons pass into breast milk. However, because this medicine may cause serious side effects, breast-feeding may not be recommended while you are receiving it. Discuss with your doctor whether or not you should breast-feed while you are receiving alpha interferon.
There is no specific information comparing use of alpha interferon for cancer or genital warts in children with use in other age groups.
Alpha interferons may cause changes in the menstrual cycle. Discuss this possible effect with your doctor.
Some side effects of alpha interferons (chest pain, irregular heartbeat, unusual tiredness, confusion, mental depression, trouble in thinking or concentrating) may be more likely to occur in the elderly, who are usually more sensitive to the effects of alpha interferons.
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. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Other medical problems
The presence of other medical problems may affect the use of alpha interferons. Make sure you tell your doctor if you have any other medical problems, especially:
• Bleeding problems-May be worsened by recombinant interferon alfa-2b
• Chickenpox (including recent exposure) or
• Herpes zoster (shingles)-Risk of severe disease affecting other parts of the body
• Convulsions (seizures) or
• Mental problems (or history of)-Risk of problems affecting the central nervous system may be increased
• Diabetes mellitus (sugar diabetes) or
• Heart attack (recent) or
• Heart disease or
• Infections or
• Kidney disease or
• Lack of blood supply to any part of the body or
• Liver disease or
• Lung disease-May be worsened by alpha interferons
• Problems with overactive immune system-Alpha interferons make the immune system even more active
• Thyroid disease-Recombinant interferon alfa-2b can cause thyroid problems when it is used to treat hepatitis
If you are injecting this medicine 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. 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.
Each package of alpha interferon contains a patient instruction sheet. Read this sheet carefully and make sure you understand:
• How to prepare the injection.
• Proper use of disposable syringes.
• How to give the injection.
• How long the injection is stable.
If you have any questions about any of this, check with your health care professional.
While you are using alpha interferon, your doctor may want you to drink extra fluids. This will help prevent low blood pressure due to loss of too much water.
Alpha interferons often cause unusual tiredness, which can be severe. This effect is less likely to cause problems if you inject your interferon at bedtime.
The dose of alpha interferons will be different for different patients. The dose that is used may depend on a number of things, including what the medicine is being used for, the patient's size, and whether or not other medicines are also being taken. If you are receiving alpha interferons at home, follow your doctor's orders or the directions on the label . If you have any questions about the proper dose of alpha interferons, ask your doctor.
If you miss a dose of this medicine, do not inject the missed dose at all and do not double the next one. Check with your doctor for further instructions.
To store this medicine:
• Keep out of the reach of children.
• Store in the refrigerator.
• Keep the medicine from freezing.
• Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.
It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.
Do not change to another brand of alpha interferon without checking with your physician . Different kinds of alpha interferon have different doses. If you refill your medicine and it looks different, check with your pharmacist.
This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before drinking alcohol or taking any of the above while you are using this medicine .
Alpha interferon may cause some people to become unusually tired or dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or if you are not alert .
This medicine commonly causes a flu-like reaction, with aching muscles, fever and chills, and headache. To prevent problems from your temperature going too high, your doctor may ask you to take acetaminophen (e.g., Anacin-3, Tylenol ) before each dose of interferon. You may also need to take it after a dose to bring your temperature down. Follow your doctor's instructions carefully about taking your temperature, and how much and when to take the acetaminophen .
Alpha interferon can lower the number of white blood cells in your blood temporarily, increasing the chance of getting an infection. It can also lower the number of platelets, which 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:
• If you can, avoid being close to people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or have painful or difficult urination.
• Check with your doctor immediately if you notice any unusual bleeding or bruising; black, tarry stools; blood in urine or stools; or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.
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.
Because this medicine is used for many different conditions and in many different doses, the actual frequency of side effects may vary. In general, side effects are less common with low doses than with high doses. Also, when alpha interferon is used for genital warts, very little of it gets into the rest of the body, so side effects are generally less common than in other conditions.
Check with your doctor as soon as possible if any of the following side effects occur:
Confusion; mental depression; nervousness; numbness or tingling of fingers, toes, and face; trouble in sleeping; trouble in thinking or concentrating.
Black, tarry stools; blood in urine or stools; chest pain; cough or hoarseness accompanied by fever or chills; fever or chills (beginning after 3 weeks of treatment); headache; irregular heartbeat; lower back or side pain accompanied by fever or chills; muscle pain; numbness or tingling in the legs; pain, swelling or redness in the joints; painful or difficult urination accompanied by fever or chills; pinpoint red spots on skin; trouble speaking; unusual bleeding or bruising.
Other 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. However, check with your doctor if any of the following side effects continue or are bothersome:
Aching muscles; change in taste or metallic taste; fever and chills (should lessen after the first 1 or 2 weeks of treatment); general feeling of discomfort or illness; headache; loss of appetite; nausea and vomiting; skin rash; unusual tiredness.
Less common or rare
Back pain; blurred vision; diarrhea; dizziness; dryness of mouth; dry skin or itching; increased sweating; joint pain; leg cramps; sores in mouth and on lips; weight loss.
Alpha interferon may cause a temporary loss of some hair. After treatment has ended, normal hair growth should return.
Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.
Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, alpha interferons are used in certain patients with the following medical conditions:
• Bladder cancer
• Carcinoid tumors
• Chronic myelocytic leukemia
• Kidney cancer
• Laryngeal papillomatosis (growths on larynx)
• Lymphomas, non-Hodgkin's
• Multiple myeloma
• Mycosis fungoides
• Ovarian cancer
• Polycythemia vera (a type of cancer of the blood)
• Skin cancer
Other than the above information, there is no additional information relating to proper use, precautions, or side effects for these uses.
This information applies to the following medicines:
1. Interferon Alfa-2a, Recombinant
2. Interferon Alfa-2b, Recombinant
3. Interferon Alfa-n1 (lns)
4. Interferon Alfa-n3
September 12, 2001