When you're first diagnosed with multiple sclerosis (MS), so many different thoughts and worries can race through your mind. How will it affect my life? Will I be able to work? Will I lose my ability to walk?
Having MS today is a lot different than it was a few decades ago. Medications like interferon beta, glatiramer acetate (Copaxone), and natalizumab (Tysabri) have literally changed the course of this disease -- for the better.
MS drugs are very effective, but they're not perfect. All of them can have side effects. Most side effects are minor, but a few -- though rare -- can be more serious.
Common Side Effects of MS Drugs
The drugs that are usually prescribed first for MS -- which include the interferons (Betaseron, Avonex, Rebif, Extavia) and Copaxone -- are considered to be very safe.
"Literally with the interferons, hundreds of thousands of patients around the world have taken these drugs successfully," says Aaron Miller, MD, medical director of the Corinne Goldsmith Dickinson Center for Multiple Sclerosis and professor of Neurology at the Mount Sinai School of Medicine. Miller consults for, and has received research support from several pharmaceutical companies that make MS drugs, including Biogen Idec, Teva, and Novartis.
Most side effects of the interferons and Copaxone are very mild. "In general, their side effects can be bothersome but aren't necessarily dangerous," says John Ratchford, MD, MSc, assistant professor of neurology at the Johns Hopkins School of Medicine. Ratchford also receives research support from several pharmaceutical companies.
With Copaxone and the interferon medications, the most common side effects are redness, warmth, or itching at the injection site, which usually fade over time. Some people notice a dimpling of the skin with repeated needle sticks. Injecting in different spots and placing a warm compress over the area before you do the injection are ways to help minimize these side effects.
Just over 10% of people who take Copaxone experience an unusual -- but brief -- reaction. Their heart races, their chest tightens, and they have trouble breathing. "You can get an idiosyncratic reaction, almost like a panic attack, immediately after the injection," Ratchford says. Though this reaction might feel like a heart attack, it isn't. The feeling should go away within 15 minutes without causing any long-term problems.
With interferon medications, it's typical to experience achiness, fatigue, a low-grade fever, soreness, and chills, which can make you feel like you've come down with a mild case of the flu. These symptoms should subside within a few weeks, but if they don't go away and they're bothersome, talk to your doctor about adjusting your medication.
Rarely, a few more serious side effects can occur with Copaxone and the interferon drugs. Interferon medications may increase the risk for depression -- which is already more common in people with MS. If you have a history of depression, your doctor may want to monitor you more closely while you're taking Avonex, Betaseron, Rebif, or Extavia. The interferon drugs can also cause liver problems and can lower the number of white blood cells, which help your body fight infection.
Another caution is with the drug Tysabri, which is used as a second-line treatment for people whose MS doesn't respond well to interferons or Copaxone. Tysabri is generally safe, but it can increase the risk for a rare but dangerous viral infection of the brain, called progressive multifocal leukoencephalopathy (PML). According to the FDA, PML incidence per 1,000 patients is 0.3 cases during the first two months of treatment, 1.5 cases during 25 to 36 months of treatment, and 0.9 during 37 to 48 months of treatment.
"Even though it's relatively rare, it's a very serious disease and often fatal or disabling, so we want to make sure we minimize the risk," Miller says. The longer patients are on this drug, the greater their risk becomes. Other conditions that increase risk for PML include AIDS, cancer, organ transplant, and chronic steroid therapy or immune suppressing therapy.
A new antibody test under development should make it easier for doctors to prescribe Tysabri. The test looks for the JC virus, which causes PML. In studies, all of the people taking Tysabri who developed PML had antibodies to the JC virus. "We assume that if you don't have this virus in your body, your risk of PML would be very low," Ratchford says. "The risk is still low, even among people who are JC-positive, but it is a little higher." Having this test available could make it easier for doctors and MS patients to decide whether taking the drug is worth the risk.
Another MS drug that can have side effects is Gilenya, which is part of a new class of MS medications and the first that can be taken by mouth. Like Tysabri, Gilenya is prescribed when other drugs haven't been effective. Its side effects include a slightly increased risk of infection, and rarely, swelling in the back of the eye (macular edema).
If your doctor is planning to prescribe Gilenya, you should get a chickenpox vaccine if you haven't already had chickenpox. In clinical trials, one person died from chickenpox while taking Gilenya. Although it isn't 100% clear that Gilenya caused the infection, "It's possible that person's ability to fight off the chickenpox virus was affected by the medication," Ratchford says. You'll also need to stay in your doctor's office to be watched for six hours the first time you get Gilenya, because it can cause a drop in heart rate after the first dose.
Working With Your Doctor to Manage Symptoms
Talking to your doctor before you start taking a new MS medication can make the potential side effects seem less frightening, and arm you with strategies to manage those side effects. "Letting them know what to expect and that it's going to improve over time goes a long way toward helping them manage those symptoms," Miller says.
It's also important to schedule regular visits to your doctor's office, especially when you start on a new drug. You'll probably see your doctor every couple of months to start, and then every six months after that, according to Ratchford.
Your doctor should give you regular blood tests to check your liver function while you are on the interferon drugs or Gilenya. People who are taking Tysabri will have to answer questions about their treatment at every monthly infusion, as part of an FDA-mandated monitoring program. Get in touch with your doctor in between scheduled visits if you see any signs of an allergic reaction (rash, swelling of the mouth), infection (fever, skin damage), or worsening of your MS.
Although you can have side effects from your MS medications, they shouldn't stop you from getting the treatment you need. Know what symptoms to watch for, get support from your doctor, and follow your treatment plan, and your MS medications should help you stay active and healthy for a long time.