Interferon Alfa-2a (Subcutaneous route)
Health Guide
Drug Guide

Interferon Alfa-2a (Subcutaneous route)


in-ter-FEER-on AL-fa-2a

Brand Names:

Dosage Forms:


Subcutaneous routeKit

Alpha-interferons, including interferon alfa-2a, cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Patients with persistently severe or worsening signs or symptoms of these conditions should be withdrawn from therapy. In many, but not all cases, these disorders resolve after stopping interferon alfa-2a therapy .

May cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Monitor closely with periodic clinical and laboratory evaluations. Discontinue therapy with persistently severe or worsening signs or symptoms of these conditions .



Immunological Agent


Interferon, Alfa (class)

Uses of This Medicine:

Interferon alfa-2a is used to treat chronic hepatitis C and certain types of leukemia (such as hairy cell leukemia and Philadelphia chromosome positive chronic myelogenous leukemia [CML]). Interferons are substances naturally produced by cells in the body to help fight infections and tumors. Interferon alfa-2a is a synthetic (man-made) version of these substances.

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

This product was withdrawn from the U.S. market by Roche on October 1, 2007. This action was not due to safety or efficacy concerns .

Before Using This Medicine:

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 this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of interferon alfa-2a in children with chronic myelogenous leukemia.

Appropriate studies have not been performed on the relationship of age to the effects of interferon alfa-2a in children with chronic hepatitis C and hairy cell leukemia. Safety and efficacy have not been established.

Older adults

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of interferon alfa-2a in the elderly. However, elderly patients are more likely to have age-related kidney problems, which may require caution in patients receiving interferon alfa-2a.


Pregnancy CategoryExplanation
All TrimestersCAnimal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

Proper Use of This Medicine:

A nurse or other trained health professional may give you this medicine. This medicine is given as a shot under your skin. You may be taught how to give this medicine at home. Make sure you understand all of the instructions before giving yourself an injection. Do not use more medicine or use it more often than your doctor tells you to.

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.

Each package of interferon alfa-2a contains a Medication Guide. Read the guide carefully and make sure you understand:

If you have any questions about any of this, check with your doctor.

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

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.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

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.


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.

Precautions While Using This Medicine:

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

This medicine contains benzyl alcohol which may cause serious reactions to newborn or premature infants. Discuss this with your doctor if you are concerned.

Interferon alfa-2a may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you, your child, or your caregiver notice any of these side effects, tell your doctor or your child's doctor right away.

Serious allergic reactions can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin; fever or chills; hives or welts; red skin lesions; severe acne or skin rash; or sores or ulcers on the skin while you are using this medicine.

Interferon alfa-2a can temporarily lower the number of white blood cells in your blood, 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:

Check with your doctor immediately if blurred vision, difficulty in reading, or any other change in vision occurs during or after treatment. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).

This medicine may cause some people to become dizzy, drowsy, 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 are not alert and not able to see well.

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

Side Effects of This Medicine:

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 immediately if any of the following side effects occur:

More common
Blurred vision
burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
chest pain
dry skin
fast, slow, or irregular heartbeat
feeling sad or empty
fever or chills
general feeling of discomfort or illness
joint pain
lack of appetite
loss of interest or pleasure
muscle aches and pains
pounding in the ears
runny nose
shortness of breath
sore throat
thickening of bronchial secretions
tightness in the chest
trouble with concentrating
trouble with sleeping
troubled breathing
unusual tiredness or weakness
weight loss
Less common
Back, leg, or stomach pains
black, tarry stools
bladder pain
bleeding gums
bloody nose
bloody or cloudy urine
changes in skin color
chest discomfort
cold feeling
collection of blood under the skin
darkened urine
deep, dark purple bruise
difficult or labored breathing
difficult, burning, or painful urination
difficulty with breathing
difficulty with moving
dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
eye pain
feeling cold
feeling of constant movement of self or surroundings
frequent urge to urinate
general body swelling
hair loss
hoarseness or husky voice
increased sweating
itching, pain, redness, or swelling
loss of bladder control
lower back or side pain
muscle cramps and stiffness
muscle spasm or jerking of all extremities
noisy breathing
pain, swelling, or redness in the joints
pain, tenderness, or swelling of the foot or leg
pains in the stomach, side, or abdomen, possibly radiating to the back
pale skin
poor concentration
redness, soreness, or itching skin
sensation of spinning
sores, ulcers, or white spots on the lips or in the mouth
sores, welting, or blisters
stomach cramps
stuffy nose
sudden loss of consciousness
swelling or inflammation of the mouth
swollen or painful glands
unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
vomiting of blood or material that looks like coffee grounds
watery or bloody diarrhea
weakness in the arms or legs
weight gain
yellow eyes or skin
bluish color of the fingernails, lips, skin, palms, or nail beds
change in consciousness
changes in the patterns and rhythms of speech
decreased vision
double vision
feeling of warmth
generalized slowing of mental and physical activity
inability to move the arms, legs, or facial muscles
inability to speak
lack of feeling or emotion
light-colored stools
loss of ability to use or understand speech or language
loss of consciousness
loss of memory
oily skin
pain or discomfort in the arms, jaw, back, or neck
pain or tenderness around the eyes and cheekbones
paleness or cold feeling in the fingertips and toes
problems with memory
problems with speech or speaking
rapid, shallow breathing
red, scaling, or crusted skin
red, sore eyes
redness of the face, neck, arms, and occasionally, upper chest
seeing, hearing, or feeling things that are not there
sensation of pins and needles
shakiness and unsteady walk
skin rash, encrusted, scaly, and oozing
slow speech
slurred speech
stabbing pain
stiff neck
sudden sweating
tingling or pain in the fingers or toes when exposed to cold
trouble sitting still
unsteadiness, trembling, or other problems with muscle control or coordination
upper right abdominal pain
Incidence not known
change in ability to see colors, especially blue or yellow
coughing that sometimes produces a pink frothy sputum
difficult, fast, or noisy breathing, sometimes with wheezing
heavier menstrual periods
migraine headache

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. Also, your health care professional may be able to tell you about ways 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
Bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
hair loss or thinning of the hair
lack or loss of strength
unable to sleep
Less common
Abnormal ejaculation
change in taste or bad unusual or unpleasant (after) taste
decreased interest in sexual intercourse
decreased sexual performance or desire
excess air or gas in the stomach or intestines
full feeling
inability to have or keep an erection
irregular menstrual period
loss in sexual ability, desire, drive, or performance
passing gas

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

Last Updated: 6/12/2013

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