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donepezil

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Brand names: Aricept

Acetylcholinesterase Inhibitor Rx

Donepezil is a medicine used to treat dementia caused by Alzheimer's disease. It can help improve memory and thinking.

Drug Pricing (NADAC)

Brand Price

$16.20/unit

Generic Price

$0.05/unit

Generic Savings

100%

Generic Available

Yes (20 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

What it does

Donepezil treats dementia in people with Alzheimer's disease.

Common side effects

Nausea, Diarrhea, Trouble sleeping

Key warnings

This medicine can slow your heart rate or cause fainting.

How It Works

Donepezil works by increasing a chemical in the brain called acetylcholine. This chemical helps nerve cells communicate better. By increasing acetylcholine, donepezil can improve mental function in people with Alzheimer's.

How to Take It

Take donepezil once a day in the evening, right before you go to bed. You can take it with or without food. If you are taking the 23 mg tablet, do not crush, split, or chew it. Your doctor may start you on a lower dose and increase it over time.

Pregnancy & Breastfeeding

Talk to your doctor if you are pregnant or plan to become pregnant. This medicine may harm your unborn baby. It is not known if donepezil passes into breast milk, so talk to your doctor if you are breastfeeding.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and take your next dose at the regular time.

Storage

Store donepezil at room temperature, away from moisture.

Side Effects (from patient reports)

Based on 18,129 FDA adverse event reports.

Falling
2,966
Death
2,021
Confusion
1,894
Diarrhea
1,739
Dizziness
1,733
Tiredness
1,687
Nausea
1,600
Medicine not working
1,532
Seeing or hearing things that are not there
1,481
Weakness
1,476

FDA Adverse Event Report Analysis

Detailed analysis of 35,138 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2003–2025.

Total Reports

35,138

Death-Related Reports

5,622

Hospitalization Reports

14,136

Top Indication

Product Used For Unknown Indication

Gender Distribution

Female 17,411 (54%)
Male 14,683 (46%)

Age Distribution

0–17 191
18–44 325
45–64 2,491
65–74 5,309
75+ 16,404

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
1 FALL 2,965
2 DEATH 2,020
3 CONFUSIONAL STATE 1,893
4 DIARRHOEA 1,738
5 DIZZINESS 1,732
6 FATIGUE 1,686
7 NAUSEA 1,599
8 DRUG INEFFECTIVE 1,532
9 HALLUCINATION 1,481
10 ASTHENIA 1,476
11 SOMNOLENCE 1,330
12 VOMITING 1,276
13 DRUG INTERACTION 1,205
14 DECREASED APPETITE 1,170
15 DYSPNOEA 1,069

Reactions in Death Reports

DEATH 2,015
FALL 598
SEPSIS 387
DYSPNOEA 363
ASTHENIA 361
CARDIO-RESPIRATORY ARREST 345
FATIGUE 340
DIZZINESS 333
DIARRHOEA 315
DECREASED APPETITE 310

Reactions in Hospitalization Reports

FALL 1,831
CONFUSIONAL STATE 842
BRADYCARDIA 753
URINARY TRACT INFECTION 728
PNEUMONIA 683
DIARRHOEA 682
SYNCOPE 659
ASTHENIA 647
NAUSEA 633
VOMITING 611

Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

This medicine can slow your heart rate or cause fainting. Tell your doctor if you have heart problems. Donepezil can also cause nausea, vomiting, and stomach bleeding. Watch for these side effects, especially when you start taking it or when your dose is increased.

Known Drug Interactions

7.2 Use with Cholinomimetics and Other Cholinesterase Inhibitors A synergistic effect may be expected when cholinesterase inhibitors are given concurrently with succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists such as bethanechol.

Mechanism: Both drugs work in a similar way to increase a specific chemical in the body. Taking them together can make this effect much stronger than intended.

What to do: Your doctor should monitor you closely for side effects if these drugs are used together. They may need to adjust your dose.

( 7.1 ) Donepezil: Increases systemic exposure of ramelteon; patients should be closely monitored when ramelteon is coadministered with donepezil. Donepezil The AUC 0-inf and C max of ramelteon increased by approximately 100% and 87%, respectively upon coadministration of donepezil with ramelteon. Patients should be closely monitored when ramelteon is coadministered with donepezil [see Clinical Pharmacology (12.5) ] .

Mechanism: Donepezil makes it harder for your body to get rid of ramelteon, leading to higher levels of the drug in your blood.

What to do: Your doctor should watch you closely for increased sleepiness or other side effects while taking both drugs.

Common Questions

What should I do if I feel sick after taking donepezil?
Tell your doctor if you have nausea, vomiting, or diarrhea. These side effects are common, but your doctor may be able to help you manage them.
Can donepezil cure Alzheimer's disease?
No, donepezil does not cure Alzheimer's disease. It can help improve symptoms, but it does not stop the disease from getting worse.
How long will I need to take donepezil?
You will likely need to take donepezil for as long as your doctor thinks it is helping you. Talk to your doctor before stopping this medicine.
Will donepezil interact with other medicines I am taking?
Donepezil can interact with some other medicines. Tell your doctor about all the medicines you take, including over-the-counter drugs and supplements.
Can I drive while taking donepezil?
Donepezil can cause dizziness or sleepiness. Be careful driving or doing anything that requires you to be alert until you know how this medicine affects you.
What dose of Donepezil should I take?
For mild to moderate Alzheimer's, start with 5mg once daily. The maximum dose is 10mg daily. For moderate to severe Alzheimer's, the maximum dose is 23mg daily.
When should I increase my dose?
Do not increase to 10mg until you have been on 5mg daily for 4-6 weeks. Do not increase to 23mg until you have been on 10mg daily for at least 3 months.
What are the inactive ingredients in the 23mg tablet?
They include colloidal silicon dioxide, hydroxypropyl cellulose, hypromellose, lactose monohydrate, magnesium stearate, and sodium starch glycolate.
What does the tablet look like?
The 23 mg tablets are reddish brown, round, and film-coated, with 'G52' on one side and 'LU' on the other.
What if I weigh less than 55kg?
Patients weighing less than 55 kg may experience more nausea, vomiting, and weight loss.
What are the common side effects of donepezil?
The most commonly reported side effects of donepezil include Nausea, Diarrhea, Trouble sleeping, Vomiting, Muscle cramps. Based on 18,129 FDA adverse event reports. Always consult your healthcare provider about potential side effects.
Does donepezil interact with other medications?
Yes, donepezil has 2 known drug interactions. Notable interactions include bethanechol, ramelteon. Always inform your doctor about all medications you are taking.
What drug class is donepezil?
donepezil belongs to the Acetylcholinesterase Inhibitor drug class. It requires a prescription (Rx). Donepezil treats dementia in people with Alzheimer's disease.
Is there a generic version of donepezil?
Yes, generic donepezil is available from 20 manufacturers. The generic costs $0.05 per unit compared to $16.20 for the brand version, saving approximately 100%. Pricing is based on NADAC (National Average Drug Acquisition Cost) data from CMS.
Is donepezil safe during pregnancy?
Talk to your doctor if you are pregnant or plan to become pregnant. This medicine may harm your unborn baby. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.

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What the FDA Data Shows for donepezil

The FDA label for donepezil (sold under brand names such as Aricept) classifies it as a prescription-only medication in the Acetylcholinesterase Inhibitor class. Donepezil treats dementia in people with Alzheimer's disease. Official labeling lists 7 commonly reported side effects, including Nausea, Diarrhea, Trouble sleeping.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 18,129 voluntary reports. The database also lists 2 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.05 versus $16.20 for the brand — a 100% generic savings.

Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.

Last updated: November 29, 2024

All federal data sources used on this page