What the label lists and what reports show
Donepezil side effects
Donepezil's FDA label: “Most common adverse reactions in clinical studies of ARICEPT are nausea, diarrhea, insomnia, vomiting, muscle cramps, fatigue, and anorexia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Eisai Inc.” FAERS holds 36,484 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fall (3,094 reports).
- Generic listed
Check it at the source: the donepezil FDA label on DailyMed (effective December 30, 2021, Eisai Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of ARICEPT?ARICEPT may cause the following serious side effects: slow heartbeat and fainting. This happens more often in people with heart problems. Call your doctor right away if you feel faint or lightheaded while taking ARICEPT. more stomach acid. This raises the chance of ulcers and bleeding, especially when taking ARICEPT 23 mg. The risk is higher for people who have had ulcers, or take aspirin or other NSAIDs. worsening of lung problems in people with asthma or other lung disease. seizures. difficulty passing urine. Call your doctor right away if you ha ve: fainting. heartburn or stomach pain that is new or won’t go away. nausea or vomiting, blood in the vomit, dark vomit that looks like coffee grounds. bowel movements or stools that look like black tar. new or worse asthma or breathing problems. seizures. difficulty passing urine. […]
Source: FDA drug label, Eisai Inc., effective December 30, 2021 (SPL set 98e451e1-e4d7-4439-a675-c5457ba20975), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions in clinical studies of ARICEPT are nausea, diarrhea, insomnia, vomiting, muscle cramps, fatigue, and anorexia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Eisai Inc.
Table 4. Adverse Reactions in Pooled Controlled Clinical Trials in Severe Alzheimer’s…
| Body System/Adverse Reaction | Placebo (n=392) % | ARICEPT (n=501) % |
|---|---|---|
| Percent of Patients with any Adverse Reaction | 73 | 81 |
| Accident | 12 | 13 |
| Infection | 9 | 11 |
| Diarrhea | 4 | 10 |
| Anorexia | 4 | 8 |
| Vomiting | 4 | 8 |
| Nausea | 2 | 6 |
| Insomnia | 4 | 5 |
| Ecchymosis | 2 | 5 |
| Headache | 3 | 4 |
| Hypertension | 2 | 3 |
| Pain | 2 | 3 |
| Back Pain | 2 | 3 |
| Eczema | 2 | 3 |
| Hallucinations | 1 | 3 |
| Hostility | 2 | 3 |
| Increase in Creatine Phosphokinase | 1 | 3 |
| Nervousness | 2 | 3 |
| Fever | 1 | 2 |
| Chest Pain | <1 | 2 |
| Confusion | 1 | 2 |
| Dehydration | 1 | 2 |
| Depression | 1 | 2 |
| Dizziness | 1 | 2 |
| Emotional Lability | 1 | 2 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following serious adverse reactions are described below and elsewhere in the labeling: Cardiovascular Conditions [see Warnings and Precautions ( 5.2 )] Nausea and Vomiting [see Warnings and Precautions ( 5.3 )] Peptic Ulcer Disease and GI Bleeding [see Warnings and Precautions ( 5.4 )] Weight Loss [see Warnings and Precautions ( 5.5 )] Genitourinary Conditions [see Warnings and Precautions ( 5.6 )] Neurological Conditions: Seizures [see Warnings and Precautions ( 5.7 )] Pulmonary Conditions [see Warnings and Precautions ( 5.8 )] Most common adverse reactions in clinical studies of ARICEPT are nausea, diarrhea, insomnia, vomiting, muscle cramps, fatigue, and anorexia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Eisai Inc. at 1-888-274-2378 (fax 1-201-746-3207) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. ARICEPT has been administered to over 1,700 individuals during clinical trials worldwide. Approximately 1200 of these patients have been treated for at least 3 months and more than 1,000 patients have been treated for at least 6 months. …
Source: FDA drug label, Eisai Inc., effective December 30, 2021 (SPL set 98e451e1-e4d7-4439-a675-c5457ba20975), via openFDA; the full label on DailyMed
What do FAERS reports show?
36,484 reports list donepezil among the medicines taken, each a report of something that happened, not proof the medicine caused it; 5,805 are coded as a death and 14,622 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 12 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Donepezil: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions