How Amantadine Helps Manage Multiple Sclerosis Symptoms

Multiple sclerosis doesn’t just cause weakness or numbness-it drains your energy like a battery that won’t hold a charge. For many people living with MS, fatigue isn’t just tiredness. It’s the kind of exhaustion that makes getting out of bed feel like climbing a mountain, and even simple tasks like brushing your teeth or making coffee become overwhelming. That’s where amantadine comes in. It’s not a cure, but for thousands of people, it’s one of the few tools that actually helps them get through the day.

What Amantadine Actually Does for MS

Amantadine was originally developed in the 1960s as an antiviral drug to fight influenza A. But doctors noticed something strange: patients taking it for the flu also reported feeling more alert and less fatigued. That led to trials in people with multiple sclerosis, and by the 1980s, it became one of the first medications officially used to treat MS-related fatigue.

It doesn’t work by reducing inflammation or slowing nerve damage like other MS drugs. Instead, amantadine affects brain chemicals-mainly dopamine and glutamate-that play a role in energy, focus, and movement. Think of it like a gentle boost to your brain’s internal battery. It doesn’t add power, but it helps your brain use what’s already there more efficiently.

Studies show that about 40% to 60% of people with MS who take amantadine report noticeable improvements in fatigue. One 2021 review of clinical trials found that patients taking amantadine scored, on average, 25% higher on fatigue scales compared to those on placebo. That might not sound like much, but for someone who can’t get out of bed without help, that’s life-changing.

Who Benefits Most from Amantadine

Not everyone with MS responds to amantadine, and it’s not a one-size-fits-all solution. People who tend to see the best results are those with relapsing-remitting MS who struggle with daytime fatigue that doesn’t improve with rest. It’s less effective for people whose fatigue is tied to heat sensitivity, depression, or poor sleep quality.

Amantadine is also sometimes used to help with leg stiffness or slow movement-symptoms that overlap with Parkinson’s. That’s because it boosts dopamine, which is involved in both motor control and energy regulation. If you’ve noticed your legs feel heavy or your steps are slower than they used to be, amantadine might help with that too.

It’s not a first-line treatment, though. Most neurologists try lifestyle changes first: better sleep, cooling vests, exercise, and pacing your day. If those don’t cut it, and fatigue is still holding you back, amantadine becomes a realistic next step.

Dosing and How It Works in Practice

Amantadine is taken as a pill, usually once or twice a day. Most people start with 100 mg daily-often in the morning-to avoid trouble sleeping. After a week or two, if there are no side effects, the dose might be increased to 200 mg per day, split into two doses (100 mg in the morning, 100 mg at lunch).

It takes time to kick in. You won’t feel better the first day. Most people notice changes after 1 to 2 weeks. Some take up to 6 weeks to feel the full effect. That’s why it’s important to stick with it, even if you don’t see results right away.

Many people take it with food to reduce stomach upset. It’s also important to avoid taking it late in the day. Even though it’s not a stimulant like caffeine, it can interfere with sleep in some people. If you’re having trouble falling asleep, talk to your doctor about switching to a single morning dose.

Side Effects and Risks

Amantadine is generally well-tolerated, but it’s not without risks. The most common side effects include:

• Lightheadedness or dizziness
• Swelling in the ankles or feet
• Insomnia or trouble sleeping
• Nausea
• Blue discoloration of the skin (livedo reticularis), especially on the legs

Less common but more serious side effects include confusion, hallucinations, or heart rhythm changes. These are rare but more likely in older adults or people with kidney problems. That’s why your doctor will check your kidney function before and during treatment. Amantadine is cleared by the kidneys, so if they’re not working well, the drug can build up to unsafe levels.

It’s also not safe to stop suddenly. If you’ve been taking it for months and decide to quit, you should taper down slowly under medical supervision. Stopping abruptly can cause withdrawal symptoms like high fever, muscle stiffness, or even delirium-similar to what happens when someone stops Parkinson’s medication too fast.

How It Compares to Other Fatigue Treatments

There are other options for MS fatigue, but each has trade-offs.

Modafinil is often seen as stronger, but it’s much more expensive and not always covered by insurance. Stimulants can help, but they carry risks of dependence and aren’t recommended for long-term use. Amantadine sits in the middle: moderate effectiveness, low cost, and fewer risks than stimulants.

Many people combine amantadine with non-drug strategies. Walking 20 minutes a day, using a cooling vest in hot weather, or scheduling rest breaks every two hours can multiply its benefits. One patient in Brisbane told me she takes amantadine in the morning, wears a cooling neck wrap at work, and takes a 30-minute nap after lunch. She says that’s the only way she can keep her job.

When Amantadine Might Not Be Right for You

There are situations where amantadine is a bad idea:

• You have kidney disease or reduced kidney function
• You’re taking other drugs that affect dopamine (like levodopa or certain antidepressants)
• You have a history of seizures or psychiatric conditions like psychosis
• You’re pregnant or breastfeeding-there’s not enough data to say it’s safe
• Your fatigue is mostly caused by depression or sleep apnea, not MS

If you’re unsure whether your fatigue is from MS or something else, your doctor should run tests. Blood work to check thyroid levels, vitamin D, iron, and sleep studies can rule out other causes. Treating those might eliminate the need for amantadine altogether.

Real Stories, Real Results

Emma, 42, was diagnosed with MS five years ago. She used to be a teacher, but by year three, she could barely make it through a school day. She tried rest, better sleep, even yoga-but nothing stuck. Her neurologist suggested amantadine. After six weeks, she noticed she could grade papers without needing a nap afterward. She started walking her dog again. She didn’t get back to 100%, but she got back to living.

James, 58, started amantadine after his MS relapse left him with heavy legs and constant exhaustion. He was on a wheelchair part-time. After two months on amantadine, he could stand for 10 minutes longer during physio. He still uses a cane, but he says, “I feel like I’m not just waiting to collapse anymore.”

These aren’t miracle stories. But they’re real. And they happen more often than most people think.

What to Do Next

If you’re struggling with MS fatigue and nothing’s helping, talk to your neurologist about amantadine. Bring a symptom diary-note when you’re most tired, what makes it worse, and what (if anything) gives you even a little boost. That helps your doctor decide if it’s worth trying.

Don’t expect it to fix everything. But if fatigue is stealing your days, amantadine might give you back a few hours. And sometimes, that’s enough.

If you’re considering amantadine, start with a conversation-not a prescription. Track your symptoms, ask questions, and give it time. The goal isn’t to feel perfect. It’s to feel like you can keep going.