Amantadine: What it treats and how to use it safely

Amantadine is a medicine you’ve probably heard about if you’re dealing with Parkinson’s symptoms, levodopa-induced dyskinesia, or certain viral infections in the past. It helps reduce involuntary movements and can ease some Parkinsonian symptoms. It’s also been used historically against influenza A, though it’s not a go-to antiviral now because many strains are resistant.

How people use amantadine

Doctors commonly prescribe amantadine for three main reasons: to help with Parkinson’s symptoms, to reduce levodopa-related dyskinesia (those jerky, involuntary movements), and sometimes off-label for fatigue in conditions like multiple sclerosis. Dosing varies by condition and by kidney function. A typical adult dose often ends up around 100 mg taken once or twice a day, but your prescriber will pick the right amount for you. Never change the dose or stop suddenly without checking with your prescriber—stopping abruptly can make movement problems worse or trigger confusion and other symptoms.

Amantadine works on brain chemicals and dopamine pathways. That’s why it can help movement, but also why it can affect mood, sleep, and thinking. If you or a caregiver notice new confusion, hallucinations, or sudden behavior changes after starting amantadine, contact your prescriber right away.

Side effects, interactions, and safety tips

Common side effects include dizziness, dry mouth, insomnia, nausea, and swelling in the legs. Some people develop a purplish skin mottling called livedo reticularis—if that happens, tell your clinician. More serious issues can include hallucinations, severe confusion, or seizures. Amantadine can lower the seizure threshold, so it needs extra caution with drugs like bupropion or if you have a history of seizures.

Kidney function matters. Amantadine is cleared by the kidneys, so people with reduced kidney function usually need lower doses. If you have kidney disease, make sure your prescriber knows so they can adjust the dose. Also mention other medicines you take—anticholinergic drugs, some antihistamines, and certain psychiatric meds can increase side effects like confusion or dry mouth.

Try to avoid driving or operating heavy machinery until you know how amantadine affects you. Feeling dizzy or sleepy is common early on. Alcohol can make dizziness and drowsiness worse, so cut back until you’re sure you tolerate the drug.

Thinking of buying amantadine online? Be careful. Use licensed pharmacies, keep a current prescription, and check that the product is legitimate. Always run medication changes by your clinician rather than self-medicating.

Quick checklist before you start amantadine: tell your prescriber if you have kidney disease, a history of seizures, heart rhythm issues, or problems thinking clearly; list every medicine and supplement you take; ask about dose adjustments and what to watch for. If side effects feel severe or sudden—like hallucinations or fainting—seek medical help immediately.

Want more detail on specific interactions or dosing for your situation? Ask your doctor or pharmacist—they’ll give guidance tailored to your health and other meds.