Patient leaflet - Amantadine Hydrochloride 100 mg capsules
1. What Amantadine Capsules are and what they are used for
Amantadine is a dopaminergic drug which means it can increase the levels of certain chemicals which transmit impulses in the nervous system, including the brain.
Amantadine Capsules are used:
to treat Parkinson’s disease by improving muscle control and reducing
stiffness, shakiness and shuffling
- in the treatment of shingles (herpes zoster), to reduce pain.
2. What you need to know before you take Amantadine Capsules
Do not take Amantadine Capsules:
if you are allergic to Amantadine hydrochloride or any of the ingredients of
Amantadine Capsules (listed in Section 6)
- if you suffer from fits (convulsions), for example epilepsy
- if you have ever had an ulcer in your stomach or small intestine
- if you suffer from any serious kidney disease
if you are pregnant or trying to become pregnant (see Section 2 Pregnancy
and breast-feeding)
- if you are breast-feeding (see Section 2 Pregnancy and breast-feeding).
If any of the above applies to you, or if you are not sure, speak to your doctor or pharmacist before you take Amantadine Capsules.
Warnings and precautions
Talk to your doctor or pharmacist or nurse before you take Amantadine Capsules if:
- you suffer from any liver or kidney disease
- you have a history of disease involving the heart and blood vessels
you are currently suffering from heart problems or heart failure (heart
problems which cause shortness of breath or ankle swelling)
- you have any mental illness for example, schizophrenia or dementia
- you have increased pressure in the eyes (glaucoma)
If any of the above applies to you, or if you are not sure, speak to your doctor or pharmacist before you take Amantadine Capsules.
Cases of suicidal thoughts and actions have been reported during treatment with amantadine. If you have thoughts or attempts of harming or killing yourself, contact your doctor immediately.
Tell your doctor if you or your family/carer notices that you are developing urges or cravings to behave in ways that are unusual for you, and you cannot resist the impulse, drive or temptation to carry out certain activities that could harm yourself or others. These are called impulse control disorders and can include behaviours such as addictive gambling, excessive eating or spending, an abnormally high sex drive or an increase in sexual thoughts or feelings.
Your doctor may need to adjust or stop your dose of Amantadine hydrochloride. If blurred vision or other visual problems occur, please contact an eye doctor immediately.
Other medicines and Amantadine Capsules
Tell your doctor or pharmacist if you are taking or have recently taken, or might take any of the following medicines as they may interfere with Amantadine Capsules:
anti-cholinergics - (used to treat Parkinson’s disease) such as
procyclidine
anti-spasmodics - (used to treat stomach spasms or cramps)
such as hyoscine
- levodopa - used to treat Parkinson’s disease
anti-psychotics - (used to improve thoughts, feelings and
behaviour when these are disturbed in certain medical conditions) such as chlorpromazine, haloperidol
diuretics (water tablets) - (used to relieve water retention and reduce high
blood pressure) such as hydrochlorothiazide, amiloride or triamterene.
Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription.
Amantadine Capsules with food and alcohol
Be careful when drinking alcohol whilst taking Amantadine Capsules, it may affect you more than usual.
Amantadine Capsules should be taken with a glass of water.
Pregnancy and breast-feeding
Do not take Amantadine Capsules if you are pregnant or trying to become pregnant.
Do not take Amantadine Capsules if you are breast-feeding because amantadine passes into breast milk and could harm your baby. Ask your doctor or pharmacist for advice before taking any medicine.
Driving and using machines
Taking Amantadine Capsules may make your vision blurred or make you feel dizzy. If you are affected, you should not drive or use machines until the effect has worn off.
Amantadine Capsules contains lactose
If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine.
3. How to take Amantadine Capsules
Always take this medicine exactly as your doctor or pharmacist has told you. You should check with your doctor or pharmacist if you are not sure. Swallow the capsules whole with a drink of water.
The usual dose is different in the following circumstances:
Parkinson’s disease
Adults: 1 capsule (100 mg) a day for the first week. Your doctor will increase this to 2 capsules a day (200 mg). Higher doses, up to 4 capsules (400 mg) a day may be given in some cases.
Adults over 65 years: 1 capsule (100 mg) once a day.
Shingles (herpes zoster)
The dose is 2 capsules (200 mg) a day for 14 days. If your pain continues your doctor may give you another 14 days treatment.
If you have kidney problems, your doctor may give you a lower dose.
If you take more Amantadine Capsules than you should
If you accidentally take too many capsules, or someone else takes any of your medicine, you should tell your doctor at once or contact the nearest accident and emergency department. Show any left-over medicines or the empty packet to the doctor.
If you forget to take Amantadine Capsules
Do not worry. If you miss a dose, take another as soon as you remember, unless it is almost time for your next dose. Then go on as before. Do not take a double dose to make up for a forgotten dose.
If you stop taking Amantadine Capsules
Do not stop taking Amantadine Capsules suddenly as your symptoms may get worse.
If you want to stop taking Amantadine Capsules, ask your doctor who will tell you how to reduce the dose gradually.
If you are taking anti-psychotics (used to treat mental disturbances) and you suddenly stop taking Amantadine Capsules, you may develop a collection of symptoms including:
- fever
- sweating
- a rapid heartbeat
- muscle stiffness (difficulty in movement)
- loss of bladder control (you may have a sudden urge to pass water) If you develop any of these symptoms you should contact your doctor immediately.
Some patients may notice that this medicine loses its effect after they have taken it regularly for a few months. If you notice this, tell your doctor. If you have any further questions on the use of this product, ask your doctor or pharmacist or nurse.
4. Possible side effects
Like all medicines, this medicine can cause side effects, although not everyone gets them. These effects are often mild and may wear off after a few days treatment. If they are severe or last more than a few days, tell your doctor or pharmacist.
If any of the following symptoms occur, you should tell your doctor or contact the nearest hospital straight away:
- convulsions (fits)
- fainting
- dizziness or light headedness
Tell your doctor or pharmacist if you think you have any of these or other problems with Amantadine Capsules:
Very common side effects (that affect more than 1 person in 10):
- swollen ankles
- red blotchy spots on the skin
Common side effects (that affect less than 1 person in 10):
- depression
- confusion
- hallucinations
- anxiety
- feeling overexcited
- difficulty sleeping
- nightmares
- feeling nervous
- headache
- feeling tired
- difficulty in controlling movements
- difficulty concentrating
- slurred speech
- fast or irregular heartbeat
low blood pressure when standing up. This may make you feel dizzy or
faint
- muscle pain
- loss of appetite
- feeling or being sick
- constipation
- sweating
- dry mouth
Uncommon side effects (that affect less than 1 person in 100):
- blurred vision
Rare side effects (that affect less than 1 person in 1000):
Neuroleptic Malignant Syndrome (NMS). You may feel hot and have
muscle stiffness
- convulsions (fits)
- shakiness
- difficulty moving
- disorientation (not knowing where you are)
- disturbed thoughts or behaviour such as feeling paranoid
loss of bladder control. You may have difficulty in passing water or have a
sudden urge to pass water
- corneal lesion, corneal oedema, reduced visual acuity
- problems with your eyes such as itchiness or redness
- skin rash
- diarrhoea
Very rare side effects (that affect less than 1 person in 10,000):
- heart problems which cause shortness of breath or ankle swelling
- reduction in the number of white blood cells which makes infections more likely
- changes in blood tests which show how the liver is working
- sensitivity to sunlight
Not known (frequency cannot be estimated from the available data):
- Urge to behave in an unusual way - strong impulse to gamble excessively, altered or increased sexual interest, uncontrollable excessive shopping or spending, binge eating (eating large amounts of food in a short time period) or compulsive eating (eating more food than normal and more than is needed to satisfy your hunger)
- Quick, involuntary muscle jerk
If any of the side effects gets worse, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.
Reporting of side effects
If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
By reporting side effects, you can help provide more information on the safety of this medicine.
5. How to store Amantadine Capsules
Keep this medicine out of the sight and reach of children.
Do not use this medicine after the expiry date which is stated on the carton. The expiry date refers to the last day of that month.
Store in the original package in order to protect from moisture. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist on how to dispose of medicines no longer required. These measures will help protect the environment.
6. Contents of the pack and other information
What Amantadine Capsules contains
The active substance in this medicine is Amantadine hydrochloride. Each hard gelatin capsule contains 100 mg Amantadine hydrochloride. The other ingredients are: lactose monohydrate, povidone, magnesium stearate.
The Capsule shell contains:
Iron oxide red (E 172), titanium dioxide (E 171), gelatin.
What Amantadine Capsules look like and contents of the pack
Amantadine Capsules are size ‘‘4’’ plain hard gelatin capsules with brownish-red colored cap and body, contains white to off white granular powder. Amantadine Capsules are available in 14 and 56s capsules. Not all pack sizes may be marketed.
Marketing Authorisation Holder and Manufacturer
Relonchem Limited,
Cheshire House, Gorsey Lane,
Widnes, Cheshire,
WA8 0RP, UK.
Product Licence Number: PL 20395/0416
This leaflet was last revised in January 2026.
If you would like this leaflet in a different format please contact the licence holder at the above address.
POM
210 mm
210 mm