What are the side effects of immunomodulatory drugs for multiple sclerosis?

Immunomodulatory drugs for multiple sclerosis (MS), like the interferon beta 1-a (Avonex, Rebif) and interferon beta 1-b (Betaseron, Extavia) drugs, have flu-like symptoms following injection, which can be minimized by taking acetaminophen (Tylenol), naproxen (Aleve), or ibuprofen (Advil or Motrin). Their less common side effects include allergic reactions, depression, suicidal ideas, liver and thyroid functions affected (altered thyroid test and elevated liver enzymes), and low red or white blood cell counts.

Because they affect the liver, you may bruise more easily or your skin may change color (make sure you inform your doctor). Avonex has been associated with heart problems, although it's not clear that the drug was the culprit. Since they are all injected, you may have localized reaction in the injection site like redness in the skin, bumps, bruises, pain, and infections. Learning how to correctly inject yourself or using autoinjecting devices may help to minimize these effects.

Glatiramer acetate (Copaxone) has a unique potential side effect that shows up right after the injection and lasts approximately 15 minutes. The person can have hot flashes and redness of the skin, chest pain, palpitations, anxiety, and difficulty breathing. It has also been reported that it can affect the results of a Pap test. Since glatiramer acetate is injectable, it can also have the injection site side effects described above.

Natalizumab (Tysabri), administered by infusion, can cause headache, fatigue, urinary tract infections, depression, lower respiratory tract infections, joint pain, and chest discomfort. It is less common to have allergic or hypersensitivity reactions within two hours of infusion (dizziness, fever, rash, itching, nausea, flushing, low blood pressure, difficulty breathing, chest pain and liver function abnormalities). This is why you have to wait at the center one hour after the infusion before leaving.

Tysabri has the risk of progressive multifocal leukoencephalopathy (PML), a serious and sometimes deadly viral infection of the brain. The risk of developing PML increases with the number of Tysabri infusions received, according to the U.S. Food and Drug Administration (FDA). In the U.S., the rate is approximately one case per 1,000 patients treated. PML symptoms may begin slowly, progress rapidly, and can include changes in thinking and memory, confusion, vision problems, difficulty walking, clumsiness, and occasional seizures.

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Ask the Experts: Multiple Sclerosis Treatments
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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.