Interferon Beta for Multiple Sclerosis
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 the natural 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 inflammation and 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 disease.2
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 MS.
How Well It Works
Studies have shown that:
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:
Call your doctor right away if you have:
Check with your doctor if you have:
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
The flu-like 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:
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.
eMedicineHealth Medical Reference from Healthwise
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