Donepezil
What is donepezil?
Donepezil is a prescription medicine used to treat the symptoms of some types of dementia. It belongs to a group of medicines called acetylcholinesterase inhibitors. It is available generically, or under brands such as Aricept[1].
What is donepezil used for?
Donepezil is used to treat the symptoms of mild to moderately severe Alzheimer’s disease. It can help improve memory, awareness, and the ability to function by increasing levels of a chemical messenger in the brain called acetylcholine. It can also help with mixed (multiple forms) dementia, but it does not cure dementia[1].
How does donepezil work?
Donepezil works by blocking the breakdown of acetylcholine, a neurotransmitter that plays a role in memory and learning. This is because people with dementia have lower levels of acetylcholine. But by preventing the breakdown of acetylcholine, donepezil helps nerve cells in the brain which can improve some symptoms of dementia[1].
Who can take donepezil?
Donepezil is prescribed for adults with mild to moderate dementia in Alzheimer's disease. However, it may not be suitable for everyone, especially if you’ve experienced[1]:
Heart conditions such as an irregular or slow heartbeat
Stomach ulcers or a history of gastrointestinal bleeding
Asthma or other lung conditions
Liver problems
A seizure or a fit
Conditions that make it hard to pee
An allergic reaction to donepezil
Donepezil is also not usually prescribed for those pregnant or breastfeeding.
Please tell your doctor or pharmacist about any conditions you may have before you start treatment and always follow the instructions in the Patient Information Leaflet[2].
How do you take donepezil?
Donepezil is usually taken once a day, preferably in the evening before bed. You can take it with or without food. Usually, you will swallow tablets whole with water. However, if you have difficulty swallowing, orodispersible tablets that dissolve on the tongue and a liquid form are also available[1].
What is the typical dosage of donepezil?
The usual starting dose of donepezil is 5mg once a day for all forms. After four to six weeks, the dose may be increased to 10mg once a day if it is well tolerated. Your doctor will decide the most appropriate dose based on your response to treatment, so please follow their guidance[1].
Can you stop taking donepezil suddenly?
You should not stop taking donepezil suddenly. Stopping the medicine may cause symptoms to return or worsen. If donepezil is no longer helping or is causing side effects, your doctor will explain how to reduce the dose gradually or switch treatments safely. Always seek medical advice before making any changes at all to how you take donepezil[1].
What should you do if you take too much donepezil?
Taking too much donepezil can cause serious side effects. The common signs of a donepezil overdose include feeling severe nausea or vomiting, drooling, and excessive sweating.
What should you do if you forget a dose of donepezil?
If you forget a dose of donepezil, skip the missed dose and take your next dose at the usual time. Do not take two doses at the same time to make up for a missed one. If you have forgotten your donepezil for more than a week, talk to your doctor before taking any more[1].
What medicines should you avoid while taking donepezil?
Donepezil interacts with several other medicines. This can be dangerous – either increasing, lowering, or changing its results. Speak to your doctor if you also take the following[1]:
Medicines for mental health such as fluoxetine, olanzapine, or risperidone
Medicines for infections such as ketoconazole, itraconazole, erythromycin, rifampicin and quinidine
Medicines used to treat heart conditions, including beta-blockers, digoxin, and verapamil
Epilepsy medication such as phenytoin or carbamazepine
Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, which may increase the risk of stomach ulcers
St John’s wort
Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2].
What are the side effects of donepezil?
Some common side effects of donepezil include nausea, diarrhoea, daytime sleepiness, headaches, difficulty sleeping, and muscle cramps. These are typically mild and pass quickly[1].
You should contact your GP or call 111 immediately if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1].
If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice.
The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2].
Frequently asked questions about donepezil
How long does it take for donepezil to work?
It usually takes at least a month to notice any improvements in symptoms when you first start taking donepezil. Speak to your doctor if you are concerned that you are not feeling the benefits after this time[1].
Will donepezil cure Alzheimer’s disease?
No, donepezil does not cure Alzheimer’s. Instead, it helps to manage symptoms and improve quality of life for those with Alzheimer's[1].
Can donepezil be taken long term?
Yes, donepezil is usually taken long term while it remains effective. Your doctor will review your treatment regularly to make sure you are experiencing the benefits of donepezil[1].
Is donepezil addictive?
No, donepezil is not addictive. However, it’s possible to experience side effects if you stop taking it, so please consult your doctor[1].
Can donepezil tablets be crushed or split?
Standard donepezil tablets should be swallowed whole with water. But if you have difficulty swallowing, speak to your doctor about other formulations like orodispersible tablets that dissolve in the mouth[1].
Can I drive whilst taking donepezil?
Donepezil may cause drowsiness or daytime sleepiness in some people, so you should not drive until you know how the medicine affects you. If you have been diagnosed with dementia you must inform the DVLA and your car insurance company straight away. You may continue to drive if it is safe to do so, some people with dementia choose to give up driving as they find it particularly stressful[1].
Can I drink alcohol whilst taking donepezil?
It is recommended to reduce or stop alcohol whilst taking donepezil. This is because alcohol can stop donepezil from working as well as it should and can also make the symptoms of dementia, such as confusion and forgetfulness, worse. It may also increase the chance of certain side effects being experienced[1].
For the official NHS guide to donepezil, visit their website.
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