Medicines & Supplements A to Z > Amantadine


Last updated on 13/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions  |   Tips  |   Where To Buy  

GENERIC NAME: Amantadine



DRUG CLASS: Antiparkinsonian agents, Antivirals

SUB CLASS: Adamantanes

USED FOR: Parkinson’s disease, Drug-induced extrapyramidal symptoms, Prevention and treatment of influenza A

– 100mg (capsules)
– 100mg (tablets)

What is Amantadine for?

Amantadine belongs to a class of medications called adamantanes. It is mainly used for the treatment of Parkinson’s disease and drug-induced extrapyramidal symptoms. On the other hand, it was once used as prophylaxis and treatment for influenza A, but it is not recommended now due to high resistance rates.

How to use it?

Amantadine can be taken orally as tablets or capsules. Listed below are the indications and the dosages, which patients with poor renal function may need a lower dose. 

For Parkinson’s disease:
100 mg once daily for the first week, and gradually increase to 200-300 mg/day.

For drug-induced extrapyramidal symptoms:
100 mg twice daily, and can be increased to 100 mg three times daily if needed.

For prevention and treatment of influenza A (not recommended):
100 mg twice daily.

What are the side effects of Amantadine?

Common side effects of Amantadine include orthostatic hypotension, peripheral oedema, dizziness, dry mouth, and syncope.

Who should not take Amantadine?

– People who are allergic to Amantadine or any component of the formulation
– Patients with severe renal impairment/disease

Pharmacist Tips:

– Avoid driving or operating machinery until you know how you respond to Amantadine as it may cause drowsiness.
– Avoid drinking alcohol during treatment
– Do not stop taking Amantadine suddenly as it may cause a serious side effect.
– Avoid getting an influenza vaccine during therapy
– Some people may develop strong urges, such as gambling, compulsive eating, compulsive buying, and increased sex drive. If you or people around you notice that you are developing unusual behaviors, talk to your doctor.

Common dosing schedule:
Amantadine can be taken with or without food.

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Amantadine may interact with:
– Antipsychotics, e.g. Risperidone, Olanzapine, Chlorpromazine
– Diuretics, e.g. Hydrochlorothiazide, Amiloride

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Amantadine in Hong Kong?

In Hong Kong, Amantadine is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

Need more information?

For detailed information about the use of Amantadine in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.