Intron A (Injection)

Interferon alfa-2b (Injection) is used to treat hepatitis B and C, lymphoma (lymph node cancer), malignant melanoma (skin cancer), genital warts, hairy cell leukemia (blood cell cancer), and Kaposi sarcoma (AIDS-related tumor). Interferons are substances made by cells in your body to help fight infections and tumors. Interferon alfa-2b is a synthetic (man-made) version of these substances.

This medicine is available only with your doctor's prescription.

It is very important for your doctor to check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Using interferon alfa-2b injection together with ribavirin while you are pregnant can harm your unborn baby. These medicines may also cause birth defects if the father is using them when his partner becomes pregnant. If you become pregnant while using these medicines, tell your doctor right away.

A negative pregnancy test is required for women of childbearing age before starting combination therapy with interferon alfa-2b injection and ribavirin. Female patients and female partners of male patients must use 2 forms of birth control during therapy and for 6 months after therapy ends. Female patients must have regular pregnancy tests during combination therapy.

This medicine may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you experience itching, hives, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, mouth, or throat.

Interferon alfa-2b injection can temporarily lower the number of white blood cells in your blood, which increases the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this happens, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If possible, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you experience 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 your urine or stools, or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your 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 since.
• Be careful not to cut yourself when using sharp objects such as safety razors or fingernail or toenail cutters.
• Avoid contact sports or any situations where bruising or injury could happen.

This medicine can increase thoughts of suicide in people with or without a history of mental illness. This medicine may also cause relapse in people with a history of substance abuse. Tell your doctor right away if you start to feel more depressed or show aggressive behavior. Also, tell your doctor right away if you have thoughts of hurting yourself or others. Report any unusual thoughts or behaviors that trouble you, especially if they are new or worsen quickly. Make sure your caregiver knows if you have trouble sleeping, get upset easily, have a big increase in energy, or start to act recklessly. Also tell your doctor if you experience sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. If you, your child, or your caregiver notice any of these side effects during treatment and up to 6 months after treatment, tell your doctor right away.

The powder form of this medicine contains albumin, which comes from human blood. Some human blood products have transmitted certain viruses to people who have received them, although the risk is low. Human donors and donated blood are both tested for viruses to keep the transmission risk low. Talk with your doctor about this risk if you have questions.

Check with your doctor if you experience blurred vision, decreased vision, or any other changes in vision during your treatment. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

This medicine may make you tired or unable to concentrate. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

Interferon alfa-2b injection and ribavirin combination may cause a dry mouth. For temporary relief of mouth dryness, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.

Some patients who have used this medicine with ribavirin have experienced vomiting. If you vomit during or after your treatment, rinse your mouth out with water. This may help prevent damage to your teeth and gums.

Children who use interferon alfa-2b and ribavirin combination may experience weight loss and slowed growth. Most children have a growth spurt and gain weight after therapy ends. If you have questions about this, talk to your doctor.

Do not take other medicines unless your doctor has discussed them with you. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

In deciding to use a medicine, you and your doctor need to consider the risks of taking the medicine versus the benefits it may provide. Here are some important points to think about:

Allergies

Inform your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also, let your healthcare professional know if you have any other allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, carefully read the label or package ingredients.

Pediatric

Studies have not shown any specific problems that would limit the use of interferon alfa-2b injection in children aged 1 to 17 years with hepatitis B or in children aged 3 to 16 years with hepatitis C.

However, studies have not been done to see how age affects the use of interferon alfa-2b injection in children with lymphoma, malignant melanoma, genital warts, hairy cell leukemia, and Kaposi sarcoma. Safety and effectiveness have not been established.

Geriatric

Studies have not found any specific problems in elderly patients that would limit the use of interferon alfa-2b injection. However, older patients are more likely to have age-related liver, kidney, bone marrow, or heart issues, which may need careful monitoring and possible dose adjustments for those receiving interferon alfa-2b injection.

Breast Feeding

There are no adequate studies to determine the risk to infants when using this medicine during breastfeeding. Weigh the potential benefits against the potential risks before using this medicine while breastfeeding.

Interactions with Medicines

Some medicines should not be used together. In other cases, two different medicines may be used together even if an interaction could happen. In these situations, your doctor may adjust the dose or take other precautions. It is very important that your healthcare professional knows if you are taking any of the medicines listed below. The following interactions have been selected based on their potential significance and do not include all possible interactions.

It is not recommended to use this medicine with the following:

• Fezolinetant

Using this medicine with any of the following is usually not recommended, but may be necessary in some cases. If both medicines are prescribed together, your doctor may adjust the dose or frequency of one or both medicines.

• Bendamustine
• Clozapine
• Pirfenidone
• Triclabendazole

Using this medicine with any of the following may increase the risk of certain side effects, but it may be necessary to use both drugs for the best treatment. If both medicines are prescribed together, your doctor may change the dose or frequency of one or both medicines.

• Ribavirin

Interactions with Food/Tobacco/Alcohol

Some medicines should not be used around the time of eating food or certain types of food due to possible interactions. Alcohol or tobacco use with certain medicines may also lead to interactions. Talk with your healthcare professional about using your medicine with food, alcohol, or tobacco.

Other Medical Problems

Other medical problems you have may affect how this medicine works. Be sure to inform your doctor if you have any other medical issues, especially:

• Autoimmune disorders (eg, psoriasis, Raynaud disease, rhabdomyolysis, rheumatoid arthritis, sarcoidosis, systemic lupus erythematosus, or vasculitis) or
• Blood clotting problems (eg, pulmonary embolism, thrombophlebitis) or
• Bone marrow problems or
• Bowel problems (eg, colitis) or
• Depression or mental illness, history of or
• Diabetes or
• Diabetic retinopathy (diabetic eye problem) or
• Eye or vision problems (eg, retinopathy, optic neuritis) or
• Heart attack, history of or
• Heart or blood vessel disease, history of or
• Heart rhythm problems (eg, arrhythmia) or
• Hypertensive retinopathy (eye problem caused by high blood pressure) or
• Hypertriglyceridemia (high triglycerides in the blood) or
• Hypotension (low blood pressure) or
• Severe liver disease (including cirrhosis) or
• Lung disease or other breathing problems (eg, COPD), history of or
• Stroke, history of or
• Thyroid problems—Use with caution. May worsen these conditions.

• Autoimmune hepatitis (liver inflammation) or
• Human immunodeficiency virus (HIV) infection or
• Severe kidney disease or
• Liver or other organ transplant or
• Sickle cell anemia (red blood cell disorder) or
• Thalassemia major (genetic blood disorder) or
• Weakened immune system—Should not be used in these cases.

• Kidney disease—Use with caution. The effects may be stronger due to slower removal of the medicine from the body.

Along with its necessary effects, a medicine may cause some unwanted effects. Not all of these side effects may occur, but if they do, they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

• Depression
• difficult or labored breathing
• swelling or puffiness of the face
• tightness in the chest
• weight loss

Less common

• Back, leg, or stomach pains
• bleeding, tender, or enlarged gums
• bloody, black, or tarry stools
• bloody nose
• bloody or cloudy urine
• blurred vision
• change in personality
• changes in behavior
• chest pain, discomfort, or heaviness
• chills
• clay-colored stools
• confusion about time, place, or person
• constipation
• cough producing mucus
• coughing or spitting up blood
• dark urine
• decreased urination
• diarrhea
• difficult or painful urination
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• drowsiness
• fainting
• fast, slow, pounding, irregular, or racing heartbeat or pulse
• feeling, seeing, or hearing things that are not there
• feeling that others are watching you or controlling your behavior
• feeling that others can hear your thoughts
• fever
• hallucinations
• headache
• hearing loss
• heavier menstrual periods
• hives or rash
• hoarseness or husky voice
• inability to speak
• increased thirst
• increased urination
• indigestion
• irritability
• itching, pain, redness, or swelling of the skin
• light-colored stools
• lightheadedness
• loss of appetite
• loss of consciousness
• loss of hearing
• lower back or side pain
• metallic taste
• muscle aches or cramps
• nausea or vomiting
• pale skin
• passing of gas
• pinpoint red spots on the skin
• seizures
• severe mood or mental changes
• severe stomach pain with nausea and vomiting
• slow speech
• sneezing
• sores, ulcers, or white spots on the lips or tongue or inside the mouth
• stiffness of the limbs
• stomach cramps, tenderness, or discomfort
• stomach pain, continuing
• stomach upset
• sweating
• swelling around the eyes
• swelling of the face, fingers, hands, ankles, feet, or lower legs
• swollen, painful, or tender lymph glands in the neck, armpit, or groin
• thoughts of hurting or killing oneself
• trouble sleeping
• unusual behavior
• unusual bleeding or bruising
• unusual tiredness or weakness
• weight gain
• yellowing of the eyes or skin

Some 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. Your health care professional may also be able to tell you how to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome, or if you have any questions about them:

More common

• Acid or sour stomach
• bleeding gums
• blistering, crusting, irritation, itching, or reddening of the skin
• body aches or pain
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• change in taste, or bad, unusual, or unpleasant (after) taste
• cracked, dry, or scaly skin
• hair loss or thinning of the hair
• irritation in the mouth
• joint pain
• lack or loss of strength
• loss of memory
• muscle or bone pain
• pain or tenderness around the eyes and cheekbones
• poor concentration
• problems with memory
• redness and swelling of the gums
• stuffy or runny nose
• swollen joints

Less common

• Abnormal ejaculation
• absent, missed, or irregular menstrual periods
• bleeding, burning, inflammation, itching, or pain at the injection site
• bone deformity
• burning, itching, and pain in the hairy areas, pus at the root of the hair
• burning, numbness, pain, or tingling in all fingers except the smallest finger
• cold and clammy skin
• decrease in height
• decreased interest in sexual intercourse
• degenerative disease of the joint
• difficulty with moving or walking
• discoloration of the skin
• inability to have or keep an erection
• increased clear or white vaginal discharge
• increased sensitivity of the skin to sunlight
• itching or pain of the genital area
• leg cramps
• longer menstrual periods
• loss in sexual ability, desire, drive, or performance
• multiple swollen and inflamed skin lesions
• pain in the ankles or knees
• pain in the ribs
• pain, inflammation, or swelling in the calves, shoulders, or hands
• painful, red lumps under the skin, mostly on the legs
• pelvic pain
• rash with flat lesions or small raised lesions on the skin
• red or irritated eyes
• redness or swelling in the arms or legs
• redness, tenderness, itching, burning, or peeling of the skin
• severe sunburn
• shivering
• skin rash, encrusted, scaly, and oozing small lumps under the skin
• small lumps under the skin
• soreness of the muscles
• stopping of menstrual bleeding
• swelling or redness in the joints
• tanning or blue-gray discoloration of the skin
• tearing of the eyes
• underactive reflexes
• unexpected menstrual bleeding

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

In the U.S.

• Intron A

Pharmacologic Class: Interferon, Alfa (class)

A nurse or other trained health professional will give you this medicine. You may also be taught how to give your medicine at home. This medicine is given as a shot under your skin, into a muscle or vein, or directly into a skin lesion.

If you are injecting interferon alfa-2b 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.

You will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas.

Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.

This medicine comes in a vial (glass container) or prefilled syringe. You might not use all of the medicine in each vial or syringe. Use them only one time and do not save an open vial or syringe. If the medicine has changed color or has particles in it, do not use it.

The solution in the vial or prefilled syringe should be allowed to warm to room temperature before injecting it.

Use a new needle and syringe each time you inject your medicine.

Drink extra fluids so you will pass more urine while you are using this medicine. This will keep your kidneys working well and help prevent kidney problems.

This medicine comes with a Medication Guide. Read this information carefully and make sure you understand:

• How to prepare the injection.
• The 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 information, talk with your doctor.

Missed Dose

This medicine needs to be given on a fixed schedule. If you miss a dose or forget to use your medicine, call your doctor or pharmacist for instructions.

Storage

Store in the refrigerator. Do not freeze.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.