Aricept, Adlarity

Introduction

Written by Helen Marshall, BPharm, MRPharmS
Medically reviewed by Victor Nguyen, PharmD, MBA
Updated on July 27, 2023

Donepezil (doh NEP e zil) is a generic medication prescribed for dementia related to Alzheimer’s disease. Donepezil belongs to a group of drugs called acetylcholinesterase inhibitors.

This article doesn’t provide coupons for all forms of donepezil. To find coupons for donepezil oral disintegrating tablet, see this article.

Side effects of donepezil

Donepezil may cause mild or serious side effects. More common mild side effects of donepezil and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about donepezil’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for donepezil listed in the “Resources” section.

Mild side effects

More common mild side effects reported with donepezil are listed below.

This article doesn’t include all possible mild side effects of the drug. To learn more about donepezil’s side effects, refer to the prescribing information for donepezil listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Mild side effects of donepezil oral tablet and orally disintegrating tablet* include:

• nausea
• vomiting
• diarrhea
• difficulty sleeping
• muscle cramps
• mild allergic reaction†

* Orally disintegrating tablets are placed on the tongue to dissolve.
† For details about this side effect, see the “Interactions and warnings for donepezil” section.

Serious side effects

Serious side effects of donepezil are listed below.

This article doesn’t include all possible serious side effects of the drug. To learn more about donepezil’s side effects, refer to the prescribing information for donepezil listed in the “Resources” section.

With many drugs, serious side effects are possible but uncommon. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

Donepezil’s serious side effects include:

• slow heart rate that may cause fainting
• ulcers (sores) or bleeding in the stomach or intestine
• difficulty urinating
• seizures
• severe allergic reaction*

* For details about this side effect, see the “Interactions and warnings for donepezil” section.

Common questions about donepezil

Below you’ll find answers to a few commonly asked questions about donepezil.

Is donepezil safe for older adults?

Yes, donepezil is generally considered safe for older adults. Dementia related to Alzheimer’s disease, which donepezil treats, mainly affects people who are more than 55 years old. (With dementia, you can have difficulty thinking, remembering, understanding, talking, and doing daily tasks.) In studies, of donepezil, side effects reported in people ages 65 years and older were similar to those reported in younger adults.

Note that as you get older, your risk of developing various health conditions can increase. And some health conditions may raise your risk of side effects with donepezil. Donepezil may be less safe for older adults with heart, lung, liver, kidney, or digestive conditions.

If you’re concerned about the safety of donepezil in older adults or those with other health conditions , talk with a doctor.

What is donepezil’s mechanism of action? How does the drug work?

Donepezil is a type of drug called an acetylcholinesterase inhibitor. It works by blocking the breakdown of a chemical in your brain called acetylcholine.

Acetylcholine works by passing messages between the nerve cells in your brain. With Alzheimer’s disease, you can have lower levels of acetylcholine than usual. This is one of the brain changes that can cause symptoms of Alzheimer’s disease. To learn about these symptoms, see the “Uses of donepezil” section.

By blocking the breakdown of acetylcholine, donepezil can help the nerve cells in your brain communicate. This may help reduce the symptoms of Alzheimer’s and slow the disease progression.

Donepezil may take a few weeks or months to start working. But this may vary between people. Some people may notice an improvement in their thinking and memory during this time. Others may not notice any change in their symptoms, but the drug may be preventing these symptoms from worsening.

If you’d like to know more about what to expect with donepezil treatment, talk with your doctor or pharmacist.

Do I need to take donepezil at night?

Yes, your doctor will likely recommend you take donepezil at night, just before going to bed. This is because the medication can make you feel dizzy.

However, if donepezil causes difficulty sleeping when you take it in the evening, talk with your doctor. They may recommend taking the medication in the morning to help avoid sleeping problems. (Difficulty sleeping is a side effect of donepezil. To learn more about the drug’s side effects, see the “Side effects of donepezil” section.)

If you have questions about takin donepezil at night, talk with your doctor or pharmacist.

Interactions and warnings for donepezil

Below, you’ll find information about donepezil’s possible interactions and warnings.

Interactions of donepezil

Certain factors may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you take donepezil, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for donepezil” section below.

Warnings for donepezil

Some people should not take donepezil and others should take it cautiously.

Donepezil could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether donepezil is a safe option for you. These warnings may differ based on the form of donepezil you take.

Ask your doctor about specific warnings for donepezil, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Donepezil can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to donepezil or any of its ingredients, your doctor will likely not prescribe donepezil. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to donepezil, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of donepezil

You should not take more donepezil than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve taken too much donepezil, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and donepezil

Information about donepezil and pregnancy and breastfeeding is described below.

Donepezil and pregnancy

It’s unknown whether donepezil should be taken during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.

Donepezil and breastfeeding

It’s unknown whether donepezil should be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication.

Uses of donepezil

The Food and Drug Administration (FDA) approves prescription drugs such as donepezil for certain conditions. Approved uses for donepezil are described below.

Use for Alzheimer’s Disease

Doctors may prescribe donepezil oral tablet and donepezil orally disintegrating tablet for treating dementia in people with mild, moderate, or severe Alzheimer’s disease. It’s used for this purpose in adults and is usually prescribed long term.

Alzheimer’s disease is a brain condition that causes dementia. With dementia, you can have difficulty thinking, remembering, understanding, talking, and doing daily tasks. With Alzheimer’s dementia, these difficulties can slowly progress over time.

Donepezil is a medication that can help nerve cells in your brain communicate. For some people, it may improve brain function and reduce the symptoms of Alzheimer’s. For others, it may slow the disease progression and symptoms. However, donepezil cannot cure Alzheimer’s. The disease can still worsen over time, even if you take donepezil.

What to ask your doctor

Let your doctor know whether you have questions about donepezil or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• How long will donepezil work for Alzheimer’s?
• How does donepezil compare with other treatments for Alzheimer’s?
• Can I take donepezil with other medications for Alzheimer’s?
• If I have side effects with donepezil, how will they be managed?

Resources

• Donepezil hydrochloride tablet, film coated; Donepezil hydrochloride tablet, orally disintegrating. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/06dd25a5-1bf2-446d-ad75-ff9d55117660/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.