Amantadine (Amantadine Hydrochloride) – Patient Information (UK)

Amantadine is a medicine used to treat certain neurological conditions and, in some situations, movement-related symptoms. It may be prescribed to help reduce the severity of symptoms and improve day-to-day functioning. This page explains what amantadine is, how it works, how it is taken, and the key safety and interaction points to know in the United Kingdom.

Important: This information is designed to help you understand your medicine. Always follow the instructions you receive from your healthcare professional and the medicine label.

Basic product information

How amantadine works (mechanism of action)

Amantadine is best known for its effects on the brain and nervous system. Its exact mechanism can vary by condition, but broadly it:

• Modulates dopamine and related signalling in the brain, which can help with some movement symptoms.
• Influences glutamate (NMDA) activity, a pathway involved in excitatory neurotransmission. This may help reduce abnormal nerve signalling that contributes to symptoms.
• May reduce involuntary movements in certain medication-related movement disorders.

Because symptom patterns differ between individuals, response can vary. Your clinician may adjust the dose over time to balance symptom relief against side effects.

Pharmacokinetics (how the body handles it)

Pharmacokinetics describes how amantadine is absorbed, distributed, metabolised, and eliminated.

• Absorption: After oral administration, amantadine is absorbed through the gut. Peak blood levels may occur a few hours after a dose (timing can vary between people).
• Distribution: It distributes into body tissues including the brain. Effects may appear after reaching adequate levels.
• Metabolism: Amantadine is not extensively metabolised.
• Elimination: The medicine is eliminated largely by the kidneys. This is why dose adjustments may be needed in kidney impairment.
• Half-life: The half-life can be prolonged in people with reduced kidney function, increasing the risk of side effects.

Practical takeaway: If you have kidney problems, it is especially important to follow dose instructions carefully and report new or worsening side effects promptly.

Typical use and indications in the UK

Amantadine is used for conditions where specialist assessment suggests it may help. Indications can vary over time and may depend on local practice, medicine availability, and updated clinical guidance.

Commonly, amantadine may be used for:

• Parkinson’s disease – to help manage certain symptoms such as tremor, rigidity, and bradykinesia, sometimes as an add-on or when other options are not suitable.
• Drug-induced extrapyramidal symptoms – including tremor, rigidity, or other movement side effects from certain antipsychotic or anti-nausea medicines (under clinical direction).
• Other neurologic or movement-related conditions – depending on specialist assessment and the evolving evidence base.

Note: Amantadine has also been researched historically for viral infections, but in everyday UK clinical practice its main role is in neurological symptom management.

When to take amantadine (timing and schedule)

The exact timing depends on your prescribed regimen and tablet/capsule strength. In general:

• Try to take it at the same times each day to maintain steady blood levels.
• If you experience insomnia or restlessness, discuss with your clinician whether your doses should be shifted earlier in the day.
• If you miss a dose, take it when you remember unless it is close to the next dose. Do not take a double dose to make up for a missed one.

If you are unsure about timing, check your label instructions or speak to a healthcare professional.

Dose and how to take it

Only your healthcare professional can determine the right dose for you. Dose is influenced by factors such as age, kidney function, and the condition being treated.

Typical approach to dosing (general information):

• Starting dose: may be lower to test tolerance, particularly in older adults or people with reduced kidney function.
• Titration: the dose may be adjusted gradually to achieve symptom control while minimising side effects.
• Maintenance dose: once an effective dose is found, it is usually continued as directed.

How to take:

• Swallow tablets/capsules with water.
• Do not crush or open capsules unless your specific product instructs you to do so.
• Keep follow-up appointments so your clinician can review response and side effects.

Kidney impairment: Because amantadine is cleared by the kidneys, reduced kidney function may require a lower dose or less frequent dosing. Never change your dose yourself.

Food interactions and eating with amantadine

Amantadine can generally be taken with or without food. However, food may affect how quickly the medicine is absorbed.

• If you are consistent (taking it the same way each day—either always with meals or always on an empty stomach), it may be easier to predict how you feel.
• If you notice stomach upset, taking it with food may help.

If you have swallowing difficulties or stomach issues, ask your pharmacist for product-specific advice.

Alcohol and medicine interactions

Alcohol

Because amantadine can cause dizziness, drowsiness, or impaired concentration in some people, alcohol may increase these effects. It is generally advisable to limit or avoid alcohol while starting or adjusting treatment, especially if you feel unsteady.

Other medicines

Amantadine can interact with other medicines. Interactions may involve changes in side effects (such as dizziness or confusion) or effects on how medicines are processed by the body.

Please tell your healthcare professional (and pharmacist) about all medicines you take, including:

• Other medicines that affect the central nervous system (for example sedatives, sleeping tablets, or some antidepressants/antipsychotics)
• Medicines that affect kidney function or urine flow (which may influence how amantadine is cleared)
• Anticholinergic medicines (may increase risk of confusion or constipation in some people)
• Medicines that influence movement symptoms (your clinician may monitor for changes in benefit or side effects)

Always check the Summary of Product Characteristics or ask your pharmacist if you start, stop, or change any medicine.

Safety profile and side effects

Most people tolerate amantadine reasonably well when taken as directed. However, side effects can occur.

Common side effects

• Dizziness or light-headedness
• Insomnia or sleep disturbance
• Nausea or loss of appetite
• Dry mouth
• Headache
• Swelling (uncommon but possible)

Less common but important side effects

• Confusion, agitation, or unusual behaviour—especially in older adults or those with kidney impairment
• Hallucinations or severe changes in mood
• Unsteady walking or falls
• Blurred vision

Seek urgent medical advice if you experience

• Severe confusion, hallucinations, or inability to stay awake
• Fainting or severe dizziness
• Signs of allergy such as rash, swelling of face/lips, or breathing difficulty

Risk factors for side effects

Side effects are more likely if you have:

• Kidney impairment (higher medicine levels may build up)
• Older age
• Neurological vulnerability or history of confusion/delirium
• Multiple medicines affecting the brain or circulation

Driving and operating machinery: If amantadine makes you dizzy, sleepy, or affects your concentration, avoid driving or hazardous activities until you know how it affects you.

Practical use tips (to get the best experience)

• Start low and go slow: If your clinician is titrating the dose, allow time for your body to adjust.
• Track symptom changes: Note improvements in movement symptoms and any worsening (e.g., tremor, stiffness) to discuss at reviews.
• Watch your sleep: If insomnia occurs, take earlier doses and speak to your pharmacist/clinician—don’t simply stop suddenly.
• Hydration and kidney health: Maintain adequate fluid intake unless you have been advised to restrict fluids.
• Stand up slowly: To reduce dizziness, especially after doses.
• Falls prevention: If you feel unsteady, ensure good lighting, remove trip hazards, and consider a mobility aid if recommended.

What to do if you miss a dose

If you miss a dose of amantadine:

• Take it as soon as you remember if it is not close to the next dose.
• If it is close to the next dose, skip the missed dose.
• Do not take two doses at once to make up for the missed one.

If you regularly miss doses, speak to your pharmacist for strategies to improve adherence.

Alternative options

Whether an alternative is suitable depends on the condition being treated and your personal medical history. For movement and neurological symptoms, clinicians may consider other medicines or non-drug approaches.

Examples of alternatives that may be discussed (not a complete list) include:

• For Parkinson’s disease symptoms: other dopaminergic therapies such as levodopa preparations, dopamine agonists, COMT inhibitors, MAO-B inhibitors, or anticholinergic medicines—chosen based on symptom pattern and side effects.
• For drug-induced movement side effects: adjusting the causative medicine, reducing dose, or switching to an alternative; in some cases, other treatments may be used depending on the situation.
• Non-medicine strategies: physiotherapy, occupational therapy, and tailored exercise programmes can support mobility and function.

Your healthcare professional can explain which option best matches your diagnosis, severity, and tolerance of side effects.

Market and legal context in the United Kingdom

In the UK, availability, prescribing practice, and patient supply arrangements are governed by national medicines policies and pharmacy regulations. Medicines like amantadine are typically dispensed through regulated pharmacy channels and may be subject to category controls depending on formulation and clinical use.

Online pharmacy availability: If ordering online, ensure the pharmacy is properly registered and follows UK regulations for medicines supply and safe patient information. A legitimate supplier will provide clear product details, correct packaging, and advice on safe use.

Regulatory updates: Like all medicines, amantadine information (including SmPC/leaflets and guidance on safe use) may be updated as new evidence emerges. Always check the patient information leaflet that comes with your medicine, and use reputable clinical sources.

Recent guidance and clinical monitoring (overview)

Clinical practice around neurological symptom management evolves with research and safety monitoring. In recent years, key themes in guidance for medicines used in movement disorders and neurological conditions have included:

• Individualised risk–benefit decisions, especially in older adults and those with cognitive symptoms.
• Kidney function awareness for medicines cleared renally.
• Careful monitoring for neuropsychiatric side effects such as confusion or hallucinations.
• Reviewing ongoing need to ensure the medicine continues to provide benefit with acceptable tolerability.

Your clinician may review symptom response and side effects periodically and may request kidney-related information (e.g., recent blood tests) if relevant to your situation.

Delivery and availability (UK)

Availability of specific strengths, capsule/tablet types, and brand names can vary. If you order online, delivery times may depend on stock status and the courier service used.

What to expect:

• Products are typically dispatched in manufacturer packaging.
• Delivery timelines can vary by location and whether the medicine is in stock.
• Keep the medicine in its original packaging and store as directed on the label or leaflet.

If you need urgent treatment changes, contact a healthcare professional or your pharmacy provider directly rather than relying on delivery timelines.

Storage

• Store at the temperature stated on the packaging (commonly “below 25°C”, but follow your specific label).
• Keep out of sight and reach of children.
• Do not use after the expiry date on the box/blister.

FAQ – Frequently asked questions

1) Is amantadine used for everyone with Parkinson’s disease?

No. Amantadine may be used in selected cases depending on symptoms, response to other treatments, overall health, and tolerance. Your clinician will decide whether it’s appropriate for you.

2) How long does it take to work?

Some people notice effects after starting, while others may require dose adjustments and several weeks to judge full benefit. Track your symptoms and discuss progress at follow-up.

3) Can I take amantadine with my other Parkinson’s medicines?

Many people do. However, medicine combinations should be managed by your healthcare professional to minimise side effects and interactions.

4) What should I do if I feel dizzy after taking it?

Do not drive. Sit or lie down until the dizziness passes. If it is frequent or severe, contact your pharmacist or clinician promptly—your dose or timing may need adjustment.

5) Are there any food restrictions?

Usually, there are no strict food restrictions. You can often take amantadine with or without food. Consistency (taking it the same way daily) can help you monitor effects.

6) Can I drink alcohol while taking amantadine?

Alcohol may increase dizziness, sleepiness, and impaired concentration. It is generally best to limit alcohol and avoid it when you’re starting or changing doses, especially if you feel unsteady.

7) What if I have kidney problems?

Tell your healthcare professional. Because amantadine is cleared by the kidneys, you may need a reduced dose or less frequent dosing to avoid accumulation and side effects.

8) What side effects are most concerning?

Confusion, hallucinations, severe drowsiness, fainting, or signs of a serious allergic reaction should be treated as urgent. Contact medical services promptly if these occur.

9) Can I stop amantadine suddenly?

Do not stop or change your dose without medical advice. If you need to discontinue, your clinician will guide you on the safest approach.

10) Are there alternatives if I can’t tolerate it?

Yes—other therapies may be considered depending on your diagnosis. Discuss options with your clinician, including both medicine and non-medicine approaches.

Disclaimer: This page provides general patient information for educational purposes. It cannot replace advice from a qualified healthcare professional. If you have questions about suitability, side effects, or interactions, contact your pharmacist or healthcare provider.