What is this medication for?

Donepezil belongs to a class of medications known as acetylcholinesterase inhibitors. It is used to reduce the symptoms of mild to moderate and severe Alzheimer’s disease and other types of dementia, such as:

• Difficulty in remembering recent events, activities, or the names of familiar people or things

• Poor concentration and judgement

It will not cure or stop the dementia from getting worse, but it may improve the ability to think in some patients and slow down the worsening of these symptoms.

Check with your healthcare professional if you are unsure why you are given this medication.

How should I take/use this medication?

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose. Then take the next dose at your usual timing. Do not take two doses to make up for the missed dose.

If you forget to take Donepezil for more than 1 week, speak to your doctor before restarting it. You may need to restart it at a lower dose.

What precautions should I take?

Inform your healthcare professional if:

• You are allergic to this medication or any of the other ingredients of this medication

• You are taking any other medications including over-the-counter medications, supplements, traditional Chinese medicine and herbal remedies. Some of these may affect how this medication works or cause serious drug interactions.

• You have or have ever had:

  • Other drug allergies

  • Medical conditions such as:

    • Heart or liver disease, slow or irregular heartbeat

    • Seizures (fits), asthma, breathing problems, stomach or intestinal ulcers, or difficulty passing urine

What are some common side-effects of this medication?

The mentioned side effects generally affect up to 10% of patients.

• Feeling tired or drowsy

  • Discuss with your doctor if you can take this medication at a different time of the day

  • Avoid driving or engaging in activities requiring concentration

• Nausea or vomiting

  • Take the medication with or after food

  • Take small but frequent meals and avoid fatty or spicy food

• Diarrhoea

• Drink plenty of water to replace fluid loss
  

• Light-headedness (especially during a sudden change in posture)

  • Get up slowly from a sitting or lying down position to avoid falling over

• Difficulty sleeping

  • Discuss with your doctor if you can take this medication at a different time of the day

  • Avoid daytime naps; listen to relaxing music at bedtime

  • Avoid overeating or drinking before bedtime

  • Limit caffeine intake to at least 8 hours before bedtime

• Headache

• Loss of appetite or weight loss

• Muscle cramps

Most of the side effects listed here will improve with time. Speak to your doctor if they are bothersome, get worse or are affecting your daily life.

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:

• Swollen face/eyes/lips/tongue

• Difficulty in breathing

• Itchy skin rashes over your whole body

Rarely this medication may cause:

• Seizures (fits)

• Fainting episodes

• Difficulty or pain in passing urine

• Slow or irregular heartbeat

• Seeing or hearing things that are not present (hallucinations)

• Anxiety or low mood

• Severe stomach pain and vomiting of blood or material that looks like coffee grounds; bloody or black tarry stools (signs and symptoms of gastrointestinal bleeding)

• Unexplained high fever, excessive sweating, confusion, severe muscle stiffness (signs and symptoms of neuroleptic malignant syndrome)

• Dark-coloured urine with unexplained muscle pain, tenderness, or weakness (signs and symptoms of rhabdomyolysis)

If you experience any of these side effects, you should stop your medication and inform your healthcare professional immediately.

Please also take note that not all possible side effects are listed above. If you have any concerns about your medication, please consult your doctor or pharmacist.

What food or medication should I avoid when I take this medication?

Avoid drinking alcohol while taking this medication as it may cause too much drowsiness.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How should I throw away this medication safely?

Pack this medication into a trash bag and seal it tightly before throwing it into the rubbish chute or bin.

Disclaimers

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Oct 2021