Avonex is injected into the muscle of the thigh, upper arm, or
buttock once a week. Rebif is injected beneath the skin 3 times a week. Betaseron
and Extavia are injected beneath the skin every other day.
How It Works
The interferon beta medicines resemble
interferon the body produces during a response by the
immune system to disease. It is not completely clear
how interferon beta medicines work in people who have
multiple sclerosis (MS). But it is known that they
affect the immune system and also help fight
viral infections. They also work by preventing
demyelination in the
central nervous system.
Why It Is Used
Interferon beta is used
to treat people with MS who have relapses followed by periods of recovery
(relapsing-remitting MS). Findings from clinical trials show that people treated soon after being diagnosed with MS may have better results than those who delay treatment.
The National Multiple Sclerosis Society recommends that people with a definite diagnosis of MS and active, relapsing disease start treatment with interferon beta or glatiramer. This group adds that treatment with medicine may also be considered after the first attack in some people who are at a high risk for MS.1
Some people have only one episode of a
neurological symptom such as
optic neuritis. Yet
MRI tests suggest these people have MS. This is known
as a clinically isolated syndrome. Many of these people go on to develop MS
over time. In some cases, doctors will prescribe medicine (either interferon
beta or glatiramer) for people who have had a clinically isolated syndrome.
These medicines, when taken early or even before you have been diagnosed with
MS, may keep the disease from getting worse or extend your time without
Interferon beta (Betaseron) has been shown to benefit people who have secondary progressive
MS that is relapsing.
The interferon beta medicines have been tested only in
people age 18 and older. But they are frequently used in children who have
How Well It Works
Studies have shown that:
- Interferon beta decreases the number of relapses in relapsing multiple sclerosis.3
- People who take interferon beta have less disability and fewer
areas of damage (lesions) on the brain as seen on MRI.3
- Treatment with interferon beta may reduce the number of attacks and slow disease progression in people who have clinically isolated syndrome and relapsing-remitting MS.4
- Treatment with interferon beta may also reduce the number of attacks and slow disease progression in people who have secondary progressive MS.5
All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.
Here are some important things to think about:
- Usually the benefits of the medicine are more important than any minor side effects.
- Side effects may go away after you take the medicine for a while.
- If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.
Call911or other emergency services right away if you have:
Call your doctor right away if you have:
Check with your doctor if you have:
Flu-like symptoms for 1 to 2 days after an injection. Symptoms may include:
Itching, swelling, or other skin changes at the injection site.
- Slow or fast heartbeat.
Common side effects of this medicine include:
See Drug Reference for a full list of side effects. (Drug
Reference is not available in all systems.)
What To Think About
symptoms—such as fatigue, chills, fever, and muscle aches—that people have for 1 to 2 days after an injection may be temporarily debilitating for some people. But these symptoms usually go away after 2 to
3 months of treatment. Taking a pain reliever such as ibuprofen or acetaminophen just before and
after each injection may help reduce these symptoms. Taking interferon beta at bedtime may also help.
Follow your doctor's instructions on how to use this medicine. Do not give yourself an injection in the same place twice in a row. Always change the site of the next injection.
Some people treated with interferon have become
depressed (feeling sad, feeling low, or feeling bad about oneself). Depression is common in people
with MS. If you are noticeably sadder or feeling more hopeless, you should tell a family member or
friend right away and call your doctor as soon as possible. You should tell the doctor if you have ever
had any mental illness, including depression, and if you take any medicines for depression.
The National Multiple Sclerosis Society recommends that people who have a definite diagnosis of MS and active, relapsing disease start treatment with interferon or glatiramer. The group adds that medicine may also be considered after the first attack in some people at high risk for MS but before it is diagnosed.1
In addition to side effects, there are some drawbacks to
treatment with interferon beta:
- Treatment does not work for some people. And
it is hard to predict whether the medicine will help a particular
- Some experts worry that in some people interferon may
become less effective after long-term use because the body may produce
antibodies that may reduce the effect of the
- Treatment is costly.
Talk with your doctor if your MS relapses have not become
less severe or less frequent after 6 months of interferon therapy. It may be
time to consider other medicines.
Medicine is one of the many tools your doctor has to treat a health problem. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.
There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.
Advice for women
Do not use this medicine if you are pregnant or planning to get pregnant. If you need to use this medicine, talk to your doctor about how you can prevent pregnancy.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
National Clinical Advisory Board of the National Multiple Sclerosis Society (2008). Disease Management Consensus Statement. New York: National Multiple Sclerosis Society. Available online: http://www.nationalmssociety.org/for-professionals/healthcare-professionals/publications/expert-opinion-papers/index.aspx.
Faggiano CM, et al. (2008). Recombinant interferon beta or glatiramer acetate for delaying conversion of the first demyelinating event to multiple sclerosis. Cochrane Database of Systematic Reviews (2).
Rowland LP (2010). Multiple sclerosis. In LP Rowland, TA Pedley, eds., Merritt’s Neurology, 12th ed., pp. 902–918. Philadelphia: Lippincott Williams and Wilkins.
Nicholas R, Chataway J (2009). Multiple sclerosis,
search date June 2008. Online version of BMJ Clinical Evidence:
Goodin DS, et al. (2002, reaffirmed 2008). Disease modifying therapies
in multiple sclerosis: Report of the therapeutics and technology assessment
subcommittee of the American Academy of Neurology and the MS Council for
Clinical Practice Guidelines. Neurology, 58(2):
Primary Medical Reviewer
||Adam Husney, MD - Family Medicine
Primary Medical Reviewer
||Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer
||Barrie J. Hurwitz, MD - Neurology
Current as of
||March 12, 2014