Relapsing multiple sclerosis (MS) is unpredictable. Because of this, many people living with MS switch treatments over the course of their condition. If you and your neurologist decide that it’s time to switch MS medications, there are steps you can take to make informed decisions so changing is easier. Knowing what to expect can help you feel more confident and prepared.

This article explains five facts you should know before making the switch. Be sure to talk with your neurologist about any questions or concerns before making a change to your treatment plan.

About MS and Disease-Modifying Therapies

MS is an autoimmune disease that affects the central nervous system (CNS) — the brain, optic nerve, and spinal cord. In MS, the immune system mistakenly attacks parts of nerve fibers, identifying them as harmful. This causes inflammation and damage, called lesions, in the CNS. Common MS symptoms include muscle weakness, fatigue, and problems with movement and vision.

Disease-modifying therapies (DMTs) — also called disease-modifying treatments or disease-modifying drugs — target inflammation in the immune system. These medications help lower the risk of relapses and slow the progression of disability. Some DMTs are referred to as highly effective — or high-efficacy (HE) — DMTs because they’ve been shown to work especially well for people with MS.

Your doctor will recommend treatment options based partly on which type of active MS you have. The four most common types are relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), primary progressive MS (PPMS), and clinically isolated syndrome (CIS).

People with MS commonly switch treatments over time to manage their condition. Reasons for switching include:

• Finding a more effective treatment due to worsening disease activity or a higher relapse rate
• Developing antibodies (immune proteins) that make a biologic drug less effective
• Avoiding side effects
• Preferring another method for taking a drug
• Seeking a less-expensive treatment
• Trying to become or being pregnant

Here are five details to consider before you switch DMTs.

1. How Long a Drug Will Take To Start Working

It’s important to understand that DMTs typically take time to become fully effective. According to a study of more than 9,000 people with MS, DMTs can take anywhere from three to 16 months to reach full effectiveness. This delay is known as therapeutic lag.

One study found that medications took an average of three to seven months to become fully effective in reducing relapse rates.

The findings showed that medications took an average of three to seven months to become fully effective in reducing the rate of MS relapses. The effect of treatment on disability progression started to show within seven to 16 months, and the lag was on the longer side for men.

In addition, some DMTs need to leave your system before you can start a new one. This washout period may delay the start of your next medication.

When you start a new treatment, your healthcare team will let you know when to follow up. They may recommend getting MRI scans and lab tests to help determine how effective your DMT is and monitor your safety over time. Talk with your neurologist about lag times and washout periods so you know what to expect. This may require patience, but it’s essential to stick to your new treatment plan once you start it.

2. How a New Medication Will Fit Into Your Life

MS treatments are given in three ways:

• IV infusion in a clinical setting
• Injections, either under the skin or directly into a muscle, via self-injection at home or in-office by a clinician
• Oral tablets

Depending on which treatment options your neurologist recommends, you may have some choice in how you take your medication. With some drugs, you may need to schedule appointments for IV infusions, which will require travel and time. With other drugs, you may have the choice between self-injection or in-clinic injection.

You’ll also need to consider how your new treatment will fit into your life. Be sure you have a clear understanding of:

• Treatment schedules
• Travel and infusion time, if your medication is given in a clinic
• Timing during the day and around meals
• Adjustments for travel, such as if the medication needs to be kept cold

Setting reminders on your phone or keeping a treatment calendar can help you manage your medication schedule and plan your other activities around it. Your neurology team may have more suggestions for sticking to a new treatment plan.

People taking certain DMTs report experiencing a “crap gap” between treatments when they don’t feel their best. Read more about this.

3. How To Manage the Risk of Side Effects

As with any drug, side effects can occur with DMTs. Each MS medication has different potential side effects, and some are more common than others. In addition, everyone’s tolerance of drugs and their side effects is different. One person may have a mild side effect that’s easy to manage, while another may have a more serious reaction. It’s important to know what side effects you might expect and how they can best be managed.

Common side effects of injected DMTs include temporary soreness at the injection site or brief flu-like symptoms. Because MS treatments lower the activity of certain cells in the immune system, they can raise the risk of infection.

Make sure you know about potential side effects and how they can best be managed.

Tell your doctor right away if you develop unexpected side effects from an MS drug. Seek help immediately if you have signs of infection or another serious complication, including:

• Shortness of breath
• Itchiness or full-body rash
• Swelling of hands or ankles
• Sudden vision problems
• Sudden numbness

Some drugs for MS — particularly HE DMTs — carry a higher risk of a condition called progressive multifocal leukoencephalopathy (PML), which is caused by a rare viral brain infection. Your doctor will carefully monitor your PML risk while you’re taking one of these drugs. Other DMTs may raise your risk of certain types of cancer.

Be sure to discuss potential side effects with your neurologist. They can help you weigh the possible risks and potential benefits of each medication and advise you on which treatment option is most likely to help you reach your treatment goals.

4. How To Pay the Lowest Out-of-Pocket Cost

Depending on your health insurance plan, DMTs can be expensive. You may discover that a recommended drug carries considerable out-of-pocket costs. Before switching DMTs due to their expense, make sure you’ve explored available resources to help with MS medication costs.

Drug companies and nonprofit organizations may provide copay help for people who meet certain income requirements. You may also be eligible for financial assistance if your condition makes it hard to manage other expenses beyond medication. A social worker can help you find resources you may be eligible for.

You may be eligible for cost assistance through the drug manufacturer or a nonprofit organization.

5. Where You Can Get Support

Switching treatments can be stressful. Stay in contact with your healthcare team so that you get the follow-up you need if you have any concerns about your medication or symptoms. Reach out to family and friends for emotional support, and let the people close to you know what you’re going through.

Social support networks like MyMSTeam offer a community of people who understand what you’re experiencing. MyMSTeam members often share their worries and experiences with switching therapies.

“My neurologist is switching me from an injected drug to an oral medication,” one member wrote. “I’m nervous and want advice.” Another member answered, “The first two weeks on the new drug were pretty rough for me. My third week has been SO much better! Most of the side effects went away, thankfully.”

After a member wrote about their fear of starting a new drug, another replied, “Please stay calm in any way you can. When you get your infusion, let the medical staff know that you are anxious. Hugs on the way to you!”

When one member shared their worries about new treatment options, another responded, “Take a breath, and just go with the flow until the pressure is off a bit.” A second member offered this advice: “Note what you want to accomplish, and don’t get overwhelmed. Breathe! Good luck.”

New Treatments for MS

In the past two decades, the U.S. Food and Drug Administration (FDA) approved more than 20 DMTs to treat MS. Newer treatments include:

• Alemtuzumab (Lemtrada)
• Cladribine (Mavenclad)
• Natalizumab (Tysabri)
• Ocrelizumab (Ocrevus)
• Ocrelizumab and hyaluronidase-ocsq (Ocrevus Zunovo)
• Ofatumumab (Kesimpta)
• Ublituximab-xiiy (Briumvi)

More new therapies, including new classes of drugs, are being investigated in clinical trials. These medications are being studied for their potential to prevent new lesions and even repair demyelination — damage to the protective myelin sheath that surrounds the nerves. With more treatment options than ever and additional choices in the pipeline, there’s reason to be hopeful that the future holds a better quality of life for people with MS.

Join the Conversation

On MyMSTeam, people share their experiences with MS, get advice, and find support from others who understand.

What else do you wish you’d known before switching MS treatments? Let others know in the comments below.