Interferon gamma-1b is made from human proteins. Interferons help the body fight viral infections.

Interferon gamma-1b is used to prevent serious infections in people with a condition called chronic granulomatous disease. Interferon gamma-1b is also used to slow the progression of a bone disorder called malignant osteopetrosis.

Interferon gamma-1b may also be used for purposes not listed in this medication guide.

Interferon gamma-1b can lower blood cells that help your body fight infections and help your blood to clot. You may get an infection or bleed more easily. Call your doctor if you have unusual bruising or bleeding, or signs of infection (fever, chills, body aches).

Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended.

Interferon gamma-1b is injected under the skin. You may be shown how to use injections at home. Do not give yourself this medicine if you do not understand how to use the injection and properly dispose of used needles and syringes.

Use only the type of syringe supplied with this medicine, or recommended by your pharmacist. Do not mix interferon gamma-1b in the same syringe with other injectable medicines.

Do not shake the medication bottle. Prepare your dose only when you are ready to give an injection. Do not use if the medicine has changed colors or has particles in it. Call your pharmacist for new medicine.

Each single-use vial (bottle) of this medicine is for one use only. Throw away after one use, even if there is still some medicine left in it after injecting your dose.

Interferon gamma-1b can lower blood cells that help your body fight infections and help your blood to clot. This can make it easier for you to bleed from an injury or get sick from being around others who are ill.

While using interferon gamma-1b, you may need frequent blood tests. Your kidney function may also need to be checked.

Tell your doctor if you have any changes in height or weight. Interferon gamma-1b doses are based on body surface area (height and weight), and any changes may affect your dose.

Store interferon gamma-1b in the refrigerator, do not freeze.

You may take the medicine out of the refrigerator and allow it to reach room temperature before injecting your dose.

Do not leave the medicine at room temperature for longer than 12 hours. Throw the medicine if it has been at room temperature for more than 12 hours. Do not put it back in the refrigerator.

Use a disposable needle and syringe only once. Follow any state or local laws about throwing away used needles and syringes. Use a puncture-proof "sharps" disposal container (ask your pharmacist where to get one and how to throw it away). Keep this container out of the reach of children and pets.

You should not use interferon gamma-1b if you are allergic to interferon gamma-1b, or to drug products made from E. coli bacteria.

To make sure interferon gamma-1b is safe for you, tell your doctor if you have:

• kidney disease;

• liver disease;

• heart rhythm problems;

• congestive heart failure;

• a nerve-muscle disorder;

• bone marrow suppression;

• a history of transient ischemic attacks (TIAs), including "mini-stroke";

• a history of seizures; or

• an allergy to rubber.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

This medicine may affect fertility (your ability to have children), whether you are a man or a woman.

It is not known whether interferon gamma-1b passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

Interferon gamma-1b is not approved for use by anyone younger than 1 year old.

Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include changes in you mental status, dizziness, loss of balance or coordination, or flu-like symptoms.

Drinking alcohol with interferon gamma-1b can cause side effects.

This medicine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Interferon gamma-1b may cause serious side effects. Call your doctor at once if you have:

• confusion, hallucinations;

• a seizure (convulsions);

• low blood cell counts--fever, chills, flu-like symptoms, swollen gums, mouth sores, skin sores, easy bruising, unusual bleeding; or

• kidney problems--little or no urination, painful or difficult urination, swelling in your feet or ankles, feeling tired or short of breath.

Your doses may be delayed or reduced if you have certain side effects.

Common side effects of interferon gamma-1b may include:

• fever, chills;

• diarrhea;

• headache;

• feeling tired;

• rash; or

• redness or tenderness where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Other drugs may interact with interferon gamma-1b, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.