A Parkinson's medicine
Amantadine
A Parkinson's medicine giving modest help with symptoms and with levodopa-related involuntary movements.
What is Amantadine?
Amantadine is used in Parkinson's disease to give modest help with symptoms such as slowness and stiffness, and is particularly useful for reducing the involuntary movements (dyskinesias) that levodopa can cause over time. Its benefit is usually milder than levodopa. It can cause a mottled, purplish skin pattern on the legs (livedo) and ankle swelling, and it may cause confusion or hallucinations, especially in older people. It should not be stopped abruptly.
Education and reference only. This is a plain-language guide to Amantadine — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Amantadine is a medicine used in Parkinson's disease, both to ease symptoms and, importantly, to reduce the involuntary movements (dyskinesias) that can develop with long-term levodopa treatment. Its effect on the core symptoms is generally modest compared with levodopa. It was originally an antiviral medicine but is now used mainly in Parkinson's. It is taken by mouth and is often added alongside other Parkinson's treatments.
How it works
Amantadine is thought to work in several ways, including increasing the activity of dopamine in the brain and blocking a glutamate (NMDA) receptor involved in movement signalling. This combination is believed to underlie its modest help with Parkinson's symptoms and its useful effect in dampening down levodopa-induced involuntary movements. The exact mechanism is not fully understood.
Company & origin
Originated / developed by: Generic (long-established).
A medicine used in the UK to help some symptoms of Parkinson's disease and the involuntary movements caused by levodopa.
What it treats
Conditions Amantadine is used for
Practical use
How to take Amantadine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it as prescribed, often earlier in the day, to reduce the chance of it disturbing your sleep.
- Tell your team if you notice ankle swelling or a mottled, purplish pattern on your legs, although this skin change is usually harmless.
- Report new confusion, vivid dreams or hallucinations, particularly important in older people.
- Do not stop it suddenly; your team will reduce it gradually if it needs to be withdrawn.
- If you miss a dose, take it when you remember unless it is nearly time for the next, then skip it and do not double up.
Weighing it up
Advantages & disadvantages of Amantadine
Advantages
- Particularly useful for reducing levodopa-induced involuntary movements (dyskinesias).
- Can give modest extra help with slowness and stiffness.
- Taken by mouth and easily combined with other Parkinson's medicines.
Disadvantages
- Its benefit on core symptoms is usually modest compared with levodopa.
- Can cause confusion, hallucinations and sleep problems, especially in older people.
- May cause ankle swelling and a mottled skin discolouration on the legs.
Practical use
Good to know
Amantadine can cause a harmless but noticeable mottled, net-like purplish discolouration of the skin, usually on the legs, called livedo reticularis, and it can cause swelling of the ankles. It may cause confusion, vivid dreams, hallucinations or difficulty sleeping, and these are more likely in older people, so it is used with care in that group. Like other Parkinson's medicines it should not be stopped abruptly, because sudden withdrawal can worsen symptoms or rarely trigger a serious reaction. Because it can be stimulating, it is often taken earlier in the day to avoid disturbing sleep.
Who should not take it / use with caution
- People with severe kidney problems need careful dose adjustment or avoidance.
- People with a history of seizures or significant confusion should use it with caution or avoid it.
- Those who have had an allergic reaction to amantadine should not take it.
Monitoring
- Review of whether symptoms or involuntary movements are improving.
- Watching for confusion, hallucinations and sleep disturbance, particularly in older people.
- Checking kidney function where relevant and looking for ankle swelling.
Side effects
- A mottled, purplish skin pattern on the legs (livedo) and ankle swelling.
- Confusion, vivid dreams, hallucinations and difficulty sleeping, especially in older people.
- Dizziness, dry mouth or nausea can also occur.
Key interactions
- Other medicines with antimuscarinic (drying) effects can add to confusion and dry mouth.
- Some medicines and alcohol can increase dizziness or central nervous system effects.
- Tell your team about all medicines, as several combinations need extra care.
Available as: Capsules and an oral liquid taken by mouth.
Answers
Amantadine: frequently asked questions
What is the mottled pattern on my legs?
Amantadine can cause a harmless net-like, purplish skin discolouration called livedo reticularis, usually on the legs; mention it to your team but it is generally not dangerous.
Will it help as much as levodopa?
Its effect on core symptoms is usually more modest than levodopa, but it can be especially helpful for reducing levodopa-related involuntary movements.
Why might I feel confused or see things?
Amantadine can cause confusion and hallucinations, more so in older people; report these to your team, who can review the dose.
Can I stop it suddenly?
No. Stopping abruptly can worsen Parkinson's symptoms or rarely cause a serious reaction, so any change should be gradual and supervised.
Why is it taken earlier in the day?
It can be stimulating and disturb sleep, so it is often taken earlier in the day rather than in the evening.
The wider class
About Parkinson's medicines
Amantadine belongs to the parkinson's medicines class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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