Pronunciation:

in-ter-FEER-on BAY-ta-1a

Brand Names:

• Avonex
• Rebif

Dosage Forms:

• Solution
• Kit

Classifications:

Therapeutic—

Immunological Agent

Pharmacologic—

Interferon, Beta (class)

Uses of This Medicine:

Interferon beta-1a is used to treat the relapsing forms of multiple sclerosis (MS). This medicine will not cure MS, but it may slow some disabling effects and decrease the number of relapses of the disease.

Interferon beta-1a is also used to treat genital warts.

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

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:

Allergies—

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.

Children—

Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of interferon beta-1a in children with use in other age groups.

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. Although there is no specific information comparing use of interferon beta-1a in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Pregnancy—

	Pregnancy Category	Explanation
All Trimesters	C	Animal 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.

Breast-feeding—

Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Other medicines—

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Rotavirus Vaccine, Live

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:

• Alcohol abuse or
• Higher concentration of a liver enzyme called SGPT
• Liver disease, active or in the past—This medicine should be used cautiously. You should tell your doctor if you have any of these conditions. If you start having symptoms of liver problems such as jaundice (yellow skin and eyes), tell your doctor right away; your medicine may need to be stopped.

• Heart disease—Some side effects of this medicine may be harmful to patients with serious heart problems
• Mental depression or thoughts of suicide or
• Psychiatric disorders or
• Other mood disorders—This medicine may make the condition worse
• Seizure disorder—The risk of seizures may be increased

Proper Use of This Medicine:

If you are injecting this medicine yourself, use it exactly as directed by your doctor.

Special patient directions come with interferon beta-1a injection. Read the directions carefully before using the medicine. 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.

Dosing—

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.

• For injection dosage form:
  • For multiple sclerosis (MS):
    • Adults
      • For Avonex
        • 30 micrograms (mcg) once a week, injected into a muscle.
      • For Rebif
        • 22 micrograms (mcg) or 44 mcg 3 times a week, injected under the skin; your doctor may start you at a lower dose at first.
    • Children—Use and dose must be determined by the physician.
  • For genital warts:
    • Adults
      • For Rebif
        • 3.67 micrograms (mcg) per lesion 3 times a week for 3 weeks

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

The next injection should be scheduled at least 48 hours later.

Storage—

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Store prefilled syringes or vials of interferon beta-1a in the refrigerator. Do not freeze. If refrigeration is not available, the vials that have not been mixed with diluent may be kept for up to 30 days at room temperature, as long as the temperature does not go above 77 °F.

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 and to check for unwanted effects.

Importance of caretaker and/or patient informing doctor of any signs or symptoms of depression or other mental or mood disturbances.

Check with your doctor right away if you experience dark urine, persistent loss of appetite, yellow eyes or skin, influenza (flu)-like symptoms, right upper quadrant tenderness, headache, stomach pain, continuing vomiting, general feeling of tiredness or weakness, or light-colored stools. These could be symptoms of serious liver problems.

You should avoid alcohol while you are taking this medicine. It can cause serious liver problems.

This medicine commonly causes a flu-like reaction, with aching muscles, chills, fever, headache, joint pain, and nausea. Your doctor may ask you to take acetaminophen to help control these effects. Follow your doctor's instructions carefully about how much and when to take acetaminophen.

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

More common

Black, tarry stools

chest pain

chills

cough

diarrhea

fever

flu-like symptoms including headache, joint pain, muscle aches, and nausea

pain

painful or difficult urination

shortness of breath

sores, ulcers, or white spots on lips or in mouth

swollen glands

unusual bleeding or bruising

unusual tiredness or weakness

Less common

Abdominal pain

chest pain

clumsiness or unsteadiness

convulsions (seizures)

coughing

decreased hearing

difficulty in swallowing

dizziness

fainting

flushing

hives or itching

mood changes, especially with thoughts of suicide

muscle spasms

pain or discharge from the vagina

pelvic discomfort, aching, or heaviness

redness, swelling, or tenderness at place of injection

runny or stuffy nose

skin lesions

sneezing

sore throat

speech problems

swelling of face, lips, or eyelids

troubled breathing

wheezing

Rare

Earache

general feeling of discomfort or illness

loss of appetite

painful blisters on trunk of body—also known as shingles

painful cold sores or blisters on lips, nose, eyes, or genitals

Incidence not known

Bleeding gums

blood in urine or stools

bloody nose

chest discomfort

confusion

constipation

continuing vomiting

convulsions

dark urine

decreased urine output

depressed mood

dilated neck veins

dry skin and hair

extreme fatigue

faintness

fast, irregular, or pounding heartbeat

feeling cold

general tiredness and weakness

hair loss

heavier menstrual periods

high fever

hoarseness or husky voice

irregular breathing

light-colored stools

loss of bladder control

mental depression

mood or other mental changes

muscle cramps and stiffness

muscle spasm or jerking of all extremities

nausea and vomiting

nervousness

pale skin

persistent anorexia

pinpoint red spots on skin

pruritus

puffiness or swelling of the eyelids, or around the eyes, face, lips, or tongue

redness, blistering, peeling, or loosening of the skin

right upper quadrant tenderness

sensitivity to heat

shortness of breath

skin rash

slowed heartbeat

stomach pain

sudden loss of consciousness

sweating

swelling of face, fingers, feet, or lower legs

swelling of the mouth or throat

tightness in chest

tightness in throat

upper right abdominal pain

vesicular rash

weight gain

weight loss

yellow eyes and 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. 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

Heartburn

indigestion

sour stomach

Less common

Hair loss

trouble in sleeping

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