Amantadine: what it treats and how to use it safely
Amantadine is a prescription medicine many people know for two things: treating Parkinson’s symptoms and treating or preventing influenza A in the past. It can help reduce tremor and stiffness in Parkinson’s and sometimes eases drug-induced movement problems. But it’s not right for everyone, and resistance makes it less useful for flu now. Here’s a practical guide to what you should know.
How amantadine works and typical uses
Amantadine boosts dopamine activity and blocks certain brain receptors (NMDA), which helps movement and can lower involuntary movements called dyskinesias. Doctors commonly prescribe it for:
- Parkinson’s disease symptoms (mild-to-moderate cases or as add-on therapy)
- Reducing dyskinesia from long-term levodopa use
- Short-term treatment or prevention of influenza A in the past (now rarely used due to resistance)
Doctors sometimes use amantadine off-label for fatigue in multiple sclerosis or other conditions, but that’s on a case-by-case basis.
Dosing basics and special situations
Common adult dosing for Parkinson’s is 100 mg once or twice daily, sometimes increased to 200 mg total per day depending on response and tolerance. For older adults or those with reduced kidney function, doctors lower the dose because the drug is cleared by the kidneys. Never change your dose without talking to your prescriber.
If you miss a dose, take it as soon as you remember unless it’s near the next scheduled dose—don’t double up. Stopping suddenly can cause problems, so any change should be gradual under medical advice.
Want to know what to watch for? Here are the key side effects and interactions.
Side effects, interactions, and safety tips
Common side effects: dizziness, dry mouth, constipation, trouble sleeping, and nausea. Some people—especially older adults—can get confusion, hallucinations, or unusual mood changes. A notable skin effect is livedo reticularis, a blotchy red-purple pattern on the skin that usually disappears after stopping the drug.
Amantadine can increase the risk of seizures in people with seizure disorders and can interact poorly with anticholinergic drugs and other medications that affect the brain. It’s cleared by the kidneys, so impaired kidney function needs dose adjustment. Pregnant or breastfeeding people should check with their doctors — safety data are limited.
If you experience severe dizziness, hallucinations, sudden swelling, breathing trouble, or a rash, contact your doctor or seek urgent care. Also tell your prescriber about all other medicines and supplements you take to avoid harmful interactions.
Need a prescription or more detailed advice? Talk with your healthcare provider. They can tailor the dose, watch for side effects, and suggest safer alternatives if amantadine isn’t a good fit.
