Multiple sclerosis (MS) has no cure. No medicine or treatment can prevent it; no medicine or treatment can cure it. However, medical research has uncovered drugs that can help prevent the relapse of symptoms and slow the pace of the disease’s progression. These drugs, called disease-modifying drugs, can improve the length and quality of life for people with MS. However, as with all medications, these drugs are not without risk.

Disease-Modifying Medications and Common Side Effects

The U.S. Food and Drug Administration (FDA) has approved nine disease-modifying medications for the treatment of MS symptoms. Here, those drugs and their most common side effects.

  • Tysabri (natalizumab ) is designed to prevent immune cells from traveling from the bloodstream into the brain and spinal cord. Research has shown natalizumab can reduce the number and severity of MS relapses. However, Tysabri comes with a note of caution from the FDA: It has been shown to increase the risk of progressive multifocal leukoencephalopathy (PML), an exceedingly rare but potentially fatal brain infection. Other, less-serious side effects of this medicine include headache, fatigue, joint pain, and allergic reactions.
  • Tecfidera (dimethyl fumarate) is an oral medicine thought to constrain immune cells and prevent them from attacking the body’s nervous system. The medicine may also act as an anti-oxidant and protect the brain and spine against further MS-related damage. Side effects of dimethyl fumarate include headache, flushing, and nausea. (4)
  • Aubagio (teriflunomide), a once-a-day oral tablet, prevents the body’s immune cells from multiplying and attacking the central nervous system. This medicine has also been shown to reduce the number of disease flares in individuals with MS. Common side effects include diarrhea, nausea, hair loss, and liver problems. (4)
  • Avonex (interferon beta-1a), a member of the interferon family of drugs, slows the progression of MS, reduces the number and size of brain lesions, and reduces the severity of disease relapse when it occurs. It is not uncommon for people receiving an interferon injection to experience flu-like symptoms (headache, chills, fever) within a few hours of the injection. Other side effects of this medicine include liver damage, seizures, and reactions at the injection site. (4)
  • Betaseron and Extavia (interferon beta-1b) have many of the same side effects as Avonex—all are members of the interferon family of drugs. People taking this medicine experience longer periods of remission between MS relapses, and when relapses occur, the severity of the relapse tends to be diminished. Side effects of interferon beta-1b include flu-like symptoms (headache, chills, fever) and reactions at the injection site. (4)
  • Rebif (interferon beta-1a) is very similar to Avonex. (Studies have shown that patients taking Rebif experience fewer relapses than patients who take Avonex.) As with other interferon drugs, patients receiving a Rebif injection are more likely to experience flu-like symptoms, especially after initial injections. (4)
  • Copaxone (glatiramer acetate) prevents the body’s immune system from destroying the myelin that protects nerves. This once-daily injection has also been shown to reduce the frequency of MS relapses. Common side effects of glatiramer acetate include reactions at the injection site, heart palpitations, chest pain, and flushing. (4)
  • Gilenya (fingolimod) was the first oral medication approved by the FDA. This once-daily tablet traps immune cells in the body’s lymph nodes, preventing attacks on myelin. Common side effects of fingolimod include increased risk of infection, increased risk of cardiac event (such as heart palpitations) following an injection, and eye toxicity. (4)
  • Novantrone (mitoxantrone) suppresses the activity of immune cells that destroy myelin. In turn, it slows disability and reduces the frequency of MS relapse. Mitoxantrone has several severe side effects—it’s been shown to cause heart damage and possibly leukemia in some patients. It is often prescribed only to patients who have not responded to other treatments.

Don’t Delay

The best possible strategy for living a healthy life with MS is working with your doctor on an effective treatment plan and evolving that treatment plan as your condition changes and new medications become available. With the advances in medicines used to treat MS, it is possible find a medicine or combination of medicines that extends the period of time between relapses and lessens the severity of relapses. Most people will never become fully disabled as a result of their MS, but the sooner you begin treatment, the better off you will be over the course of your lifetime. It is not entirely clear what the effects of delaying treatment are, but research does show that the sooner you start treatment, the better you are likely to fare in the initial years after the diagnosis. Early treatment can slow the speed of disability, decrease the damage done to the body’s nervous system, and in many cases, help the person with MS live a healthier, happier, more productive life.