Multiple sclerosis is a nervous system disease in which the immune system of the body attacks the coverings of the nerves. This leads to damage to the nerves themselves, which causes symptoms such as numbness, difficulties with balance and changes in vision. There is no cure for multiple sclerosis, but several medications are available that may manage the course of the disease, manage symptoms and treat flare-ups of the disease, according to the National Multiple Sclerosis Society. These medications do have some side effects, however, which may occur after administration.
Flu-Like Symptoms
Three of the available medications that can be used long term to treat multiple sclerosis---Betaseron, Avonex and Rebif---are all interferon medications. According to the University of Maryland Medical Center website, these medications can cause an increase in body temperature, which can lead to flu-like symptoms, including chills, headache and fatigue. The symptoms last for about 12 hours and tend to be less frequent as the treatment proceeds.
Irritation at the Injection Site
The interferons Betaseron and Rebif and another medication, glatiramer acetate, or Copaxone, can cause a reaction at the area of injection such as redness or swelling, as noted on the University of Maryland Medical Center website. The interferon Avonex can cause bruising and discomfort and pain at the site of injection because it is administered in the muscle.
Immune System Suppression
The medication mitoxantrone, or Novantrone, can cause immune system suppression. While the risk of infection is increased after administration in these patients, the risk does not last very long, as noted on the University of Maryland Medical Center website.
Liver Failure
The interferon medications can also cause liver damage, according to the University of Maryland Medical Center website. Patients need frequent blood tests to measure liver function while taking these drugs.
Heart Failure
Mitoxantrone can cause heart failure if used for long periods of time, according to the Mayo Clinic. Typically this drug can only be given for two or three years at most, and the patients who receive it must be continually tested for heart damage, according to the Multiple Sclerosis Association of America. Mitoxantrone is usually only given to patients with advanced cases of multiple sclerosis.
Post-Injection Reaction
Glatiramer acetate can cause a reaction after injection in about 10 percent of people who take the medication, according to the University of Maryland Medical Center website. This reaction consists of shortness of breath, anxiety, dizziness and an irregular heartbeat; the reaction usually only lasts for about 10 minutes and does not cause any long-term problems.
Progressive Multifocal Leukoencephalopathy
According to the Mayo Clinic, the medication natalizumab, or Tysabri, increases the risk of a viral brain infection called progressive multifocal leukoencephalopathy. This infection is often deadly and patients who take this medication are monitored for it, as noted by the Multiple Sclerosis Association of America website. Because of this risk, this medication is mainly used in patients who cannot handle other medications or have gotten no results from any of them.
