Amantadine Dosage: What You Need to Know About Dosing, Side Effects, and Uses
When you hear amantadine, a medication used to treat Parkinson’s disease and certain types of influenza. Also known as Symmetrel, it’s one of the older drugs still in use because it works differently than most—helping the brain manage movement and blocking flu viruses from spreading. It’s not a typical painkiller or antibiotic. You take it for specific reasons, and the dose you need depends entirely on why you’re taking it.
For Parkinson’s disease, a neurological disorder causing tremors, stiffness, and slow movement, doctors usually start with 100 mg once daily. After a week or two, they might bump it up to 100 mg twice a day if you need more control over symptoms. But if you’re older or have kidney problems, you might stay on the lower dose. Too much can make you dizzy, confused, or even cause hallucinations. That’s why you don’t just take more if you feel it’s not working—talk to your doctor first.
For influenza prevention, especially during flu season or after exposure, the standard dose is also 100 mg once a day. But here’s the catch: it only works against certain flu strains, like H1N1, and it’s not a replacement for the flu shot. It’s used when the vaccine isn’t enough or when you’re at high risk. You start taking it as soon as possible after exposure, and keep going for at least 10 days. If you’re using it to treat active flu, you take it for 3 to 5 days, starting within 48 hours of symptoms.
What you need to avoid is mixing amantadine with other drugs that affect the brain or kidneys. Anticholinergics, SSRIs, and even some cold medicines can make side effects worse. If you’re on kidney disease, a condition that reduces how well your kidneys filter waste, your dose might need to be cut in half—or even skipped. Your kidneys clear amantadine from your body. If they’re not working right, the drug builds up, and that’s when trouble starts.
Some people take it for fatigue from multiple sclerosis, though that’s off-label. Others use it for restless legs or even depression, but those uses aren’t FDA-approved. The science is still catching up. What’s clear is that this isn’t a drug you can adjust on your own. It’s not like taking ibuprofen for a headache. One wrong dose, especially in older adults, can lead to falls, confusion, or worse.
Below, you’ll find real posts that dig into what happens when amantadine meets other meds, how it compares to newer Parkinson’s treatments, and why some people stop taking it because of side effects. You’ll also see how doctors decide who gets it and who doesn’t—based on kidney health, age, and what else they’re taking. No guesswork. No fluff. Just what you need to know to stay safe and get the most from this old-school drug.
Learn practical ways to manage common amantadine side effects like dizziness, insomnia, and swelling. Discover dose tips, hydration strategies, and when to call your doctor.
Dec, 1 2025