Sounds like 'doe-nep-e-zil'

Donepezil is used to treat dementia associated with Alzheimer's disease. Find out how to take it safely and possible side effects. Donepezil is also called Aricept.

Type of medicine Also called
  • Medicines for dementia
  • Belongs to a group of medicines known as cholinesterase inhibitors
  • Aricept®
  • Donepezil (Rex)®

What is donepezil?

Donepezil is in a class of medications called cholinesterase inhibitors. It is used to treat dementia associated with Alzheimer's disease. Donepezil helps to ease the symptoms of mild to moderate dementia in Alzheimer's disease, such as memory loss, but does not cure it. Donepezil works by increasing the amount of a chemical in the brain called acetylcholine, which is known to be lower in people suffering from dementia in Alzheimer's disease. Read more about medicines for dementia.

In New Zealand donepezil is available as tablets (5 mg and 10 mg). 


  • The usual starting dose of donepezil is 5 milligrams daily.
  • After at least 1 month, your doctor will assess your response and may increase your dose to 10 milligrams daily.
  • Always take your donepezil exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much donepezil to take, how often to take it and any special instructions.
  • You will need to see your doctor regularly to check your response to treatment, if the dose is right and if this medicine is right for you. 

How to take donepezil?

  • Take donepezil once a day, in the evening before bedtime.
  • You can take donepezil with or without food.
  • Keep taking donepezil every day. It may take a while before you experience the full benefits of the medication.
  • Donepezil tablets are available in different strengths (5 mg and 10 mg). Check with your pharmacist if your tablets are different to what you expect.
  • It is important that you take donepezil each night. If you forget to take your dose, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.
  • If you forget to take donepezil for more than a few days, talk with your doctor before starting to take it again. You may need to restart donepezil on a lower dose. Read more about tips when taking medicines for dementia.   

Precautions before starting donepezil

  • Do you have problems with your liver?
  • Do you have any heart problems such as an irregular heart beat?
  • Do you have problems with your breathing such as asthma or COPD?
  • Do you have problems passing urine (peeing)?
  • Do you have epilepsy?
  • Have ever had a stomach (gastric) or duodenal ulcer?
  • Are you taking any other medicines, including medicines you can buy without a prescription, such as herbal and complementary medicines, or antihistamines for hay fever or pain relief medicines?

If so, it’s important that you tell your doctor or pharmacist before you start donepezil. Sometimes a medicine isn’t suitable for a person with certain conditions or it can only be used with extra care.

What are the side effects of donepezil?

Like all medicines, donepezil can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine

Side effects What should I do?
  • Nausea (feeling sick) or vomiting
  • Try taking donepezil with food or a snack and make sure you are drinking enough water.
  • Tell your doctor if troublesome; they may recommend a lower dose.
  • Loss of appetite
  • Headache
  • Diarrhoea (runny poos)
  • These are quite common when you first start taking donepezil and usually go away with time.
  • Tell your doctor if troublesome. 
  • Trouble sleeping, strange dreams, hallucinations, agitation
  • Tell your doctor.
  • Muscle cramps, itch, rash
  • Tell your doctor immediately or ring HealthLine 0800 611 116.
  • Tiredness
  • Dizziness
  • Feeling faint
  • Try getting up or moving slowly.
  • If you begin to feel faint, sit or lie down until the feeling passes.
  • Avoid driving until you know how this medicine affects you.
  • Do not drink alcohol.
  • Tell your doctor if this continues.
  • Signs of stomach problems such as really bad tummy pain, blood in your stool or black stools, vomit blood or dark-coloured vomit.
  • Tell your doctor immediately or ring HealthLine 0800 611 116.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product

Learn more

Medsafe Consumer Information Sheet Aricept 


  1. The pharmacological management of Alzheimer’s disease – the place of donepezil BPAC, NZ, 2010
  2. Antipsychotics in dementia – best practice guide BPAC, NZ
  3. Managing patients with dementia – what is the role of antipsychotics? BPAC, NZ, 2013
  4. Donepezil New Zealand Formulary

Additional resources for healthcare professionals

Aricept Medsafe, NZ
Donepezil Medsafe, NZ
Interactions with donepezil Medsafe, NZ, 2017
Donepezil – syncope, heart block and beta-adrenergic blockade Medsafe, NZ, 2013
Having a senior moment? Differentiating normal age-related memory loss from early onset dementia BPAC, NZ, 2009
Donepezil – safe prescribing  – don't forget SAFERx, NZ, 2019

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 02 Apr 2019