In the U.S.—

• Biological response modifier

Interferon ( in-ter-FEER-on) is a substance naturally produced in cells in the body to help fight infections. There also are synthetic (man-made) versions of this substance, such as interferon alfacon-1. Interferon alfacon-1 is used to treat hepatitis C, a type of infection of the liver, in adults who also have other types of liver disease.

This medicine is available only with your doctor's prescription, in the following dosage form:

Parenteral
• Injection (U.S.)

In deciding to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For interferon alfacon-1, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to interferon alfacon-1 or to any other alpha interferon. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Interferon alfacon-1 has not been studied in pregnant women. However, studies in animals have shown that interferon alfacon-1 causes the fetus to abort and other problems. Before taking this medicine, make sure your doctor knows if you are pregnant or if you plan to become pregnant.

Breast-feeding—It is not known whether interferon alfacon-1 passes into breast milk. However, because this medicine may cause serious side effects in nursing babies, breast-feeding may not be recommended while you are receiving it. Discuss with your doctor whether you should breast-feed while you are receiving interferon alfacon-1.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of interferon alfacon-1 in children with use in other age groups. However, use in children less than 18 years of age is not recommended.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of interferon alfacon-1 in the elderly with use in other age groups.

Other medicines—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.

• Decreased bone marrow production or other blood problems or
• Heart disease or
• Liver disease or
• Mental problems (or history of) or
• Thyroid disease—Interferon alfacon-1 may make these conditions worse

• Problems with an overactive immune system—Interferon alfacon-1 may make the immune system even more active

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.

To help clear up your infection completely, interferon alfacon-1 must be used for the full time of treatment, even if you begin to feel better after a few days or weeks. It is also very important that you receive your injection at the same time for each day of treatment.

Each package of interferon alfacon-1 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.

Dosing—

The dose of interferon alfacon-1 will be different for different patients. If you are receiving interferon alfacon-1 at home, follow your doctor's orders or the directions on the label . If you have any questions about the proper dose of interferon alfacon-1, ask your doctor.

• For injection dosage form:
  • For hepatitis C:
    • Adults—9 micrograms per dose, injected under the skin, three times per week at intervals of at least forty-eight hours, for twenty-four weeks.
    • Children—Use is not recommended.

Missed dose—

If you miss a dose of this medicine, do not give the missed dose at all and do not double the next one. Check with your doctor for further instructions.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store in the refrigerator. However, 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. It is also important that you tell your doctor if you notice any changes in your ability to see clearly.

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 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 before each dose of interferon alfacon-1. You may also need to take acetaminophen after a dose of interferon alfacon-1 to bring your temperature down. Follow your doctor's instructions carefully about taking your temperature, and how much and when to take the acetaminophen.

In some patients, this medicine may cause mental depression. Tell your doctor right away:

• if you or anyone else notices unusual changes in your mood.
• if you start having early-morning sleeplessness or unusually vivid dreams or nightmares.

Interferon alfacon-1 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 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 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.

Interferon alfacon-1 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.

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 as soon as possible if any of the following side effects occur:

• More common
  • Anxiety;  black, tarry stools;  blood in urine or stools;  confusion ;  cough or hoarseness;  fever or chills;  lower back or side pain;  mental depression;  nervousness;  painful or difficult urination;  pinpoint red spots on skin;  redness at place of injection ;  trouble in sleeping;  trouble in thinking or concentrating;  unusual bleeding or bruising 
  
  

• Less common
  • Chest pain;  irregular heartbeat;  numbness or tingling of fingers, toes, or face 
  
  

• Rare
  • Blurred vision or loss of vision;  skin rash, hives, or itching 
  
  

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:

• More common
  • Abdominal pain;  aching muscles;  decreased appetite;  diarrhea;  dizziness;  general feeling of discomfort or illness;  headache;  heartburn or indigestion;  nausea or vomiting;  pain in back or joints;  sore throat ;  unusual tiredness or weakness 
  
  

Interferon alfacon-1 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.