Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
Quick facts
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 997220
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
Donepezil hydrochloride is an acetylcholinesterase inhibitor indicated for the treatment of dementia of the Alzheimer's type. Efficacy has been demonstrated in patients with mild, moderate, and severe Alzheimer's Disease ( 1 ) Donepezil hydrochloride is indicated for the treatment of dementia of the Alzheimer's type. Efficacy has been demonstrated in patients with mild, moderate, and severe Alzheimer's disease.
About this medicine
Donepezil hydrochloride is a reversible inhibitor of the enzyme acetylcholinesterase, known chemically as (±)-2, 3-dihydro-5, 6-dimethoxy-2-[[1-(phenylmethyl)-4-piperidinyl]methyl]-1 H -inden-1-one hydrochloride. Donepezil hydrochloride is commonly referred to in the pharmacological literature as E2020. It has a molecular formula of C 24 H 29 NO 3 HCl and a molecular weight of 415.96. Donepezil hydrochloride is a white crystalline powder and is freely soluble in chloroform, soluble in water and in glacial acetic acid, slightly soluble in ethanol and in acetonitrile, and practically insoluble in ethyl acetate and in n-hexane. Donepezil hydrochloride is available for oral administration in film-coated tablets containing 5 and 10 mg of donepezil hydrochloride. Inactive ingredients in 5 mg and 10 mg tablets are lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, magnesium stearate. The film coating contains talc, polyethylene glycol, polyvinyl alcohol and titanium dioxide. Additionally, the 10 mg tablet contains yellow iron oxide as a coloring agent. Donepezil hydrochloride orally disintegrating tablets USP are available for oral administration. Each Donepezil hydrochloride orally disintegrating tablet USP contains 5 or 10 mg of donepezil hydrochloride. Inactive ingredients are mannitol, silicified microcrystalline cellulose, low substituted hydroxypropyl cellulose, sucralose, orange flavor,sodium stearyl fumarate. Additionally, the 10 mg tablet contains iron oxide yellow as a coloring agent. Molecular Structure
How it works
12.1 Mechanism of Action Current theories on the pathogenesis of the cognitive signs and symptoms of Alzheimer's disease attribute some of them to a deficiency of cholinergic neurotransmission. Donepezil hydrochloride is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine through reversible inhibition of its hydrolysis by acetylcholinesterase. There is no evidence that donepezil alters the course of the underlying dementing process.
Who should not take it
Known hypersensitivity to donepezil hydrochloride or to piperidine derivatives ( 4 ) Donepezil hydrochloride is contraindicated in patients with known hypersensitivity to donepezil hydrochloride or to piperidine derivatives.
Warnings
PATIENT PACKAGE INSERT Donepezil Hydrochloride Tablets USP (doe nep' e zil hye'' droe klor' ide) Tablets: 5 mg and 10 mg Donepezil Hydrochloride Orally Disintegrating Tablets USP (doe nep' e zil hye'' droe klor' ide oh-dee-tee) ODT Tablets: 5 mg and 10 mg Read this Patient Information that comes with donepezil hydrochloride tablets and donepezil hydrochloride ODT before you start taking it and each time you get a refill. There may be new information. This leaflet does not take the place of talking with your doctor about Alzheimer's disease or treatment for it. If you have questions, ask the doctor or pharmacist. What is donepezil hydrochloride? Donepezil hydrochloride comes as donepezil hydrochloride film-coated tablets in dosage strengths of 5 mg and 10 mg, and as donepezil hydrochloride orally disintegrating tablets (ODT; 5 mg and 10 mg). Except where indicated, all the information about donepezil hydrochloride tablets in this leaflet also applies to donepezil hydrochloride ODT. Donepezil hydrochloride is a prescription medicine to treat mild, moderate, and severe Alzheimer's disease. Donepezil hydrochloride can help with mental function and with doing daily tasks. Donepezil hydrochloride does not work the same in all people. Some people may: Seem much better Get better in small ways or stay the same Get worse over time but slower than expected Not change and then get worse as expected Donepezil hydrochloride does not cure Alzheimer's disease. All patients with Alzheimer's disease get worse over time, even if they take donepezil hydrochloride. Donepezil hydrochloride has not been approved as a treatment for any medical condition in children. Who should not take donepezil hydrochloride? Do not take donepezil hydrochloride if you are allergic to any of the ingredients in donepezil hydrochloride tablets and donepezil hydrochloride ODT or to medicines that contain piperidines. Ask your doctor if you are not sure. See the end of this leaflet for a list of ingredients in donepezil hydrochloride tablets and donepezil hydrochloride ODT. […]
Warnings and cautions
Cholinesterase inhibitors are likely to exaggerate succinylcholine-type muscle relaxation during anesthesia ( 5.1 ) Cholinesterase inhibitors may have vagotonic effects on the sinoatrial and trioventricular nodes manifesting as bradycardia or heart block ( 5.2 ) Donepezil hydrochloride can cause vomiting. Patients should be observed closely at initiation of treatment and after dose increases ( 5.3 ) Patients should be monitored closely for symptoms of active or occult gastrointestinal (GI) bleeding, especially those at increased risk for developing ulcers ( 5.4 ) The use of donepezil hydrochloride in a dose of 23 mg once daily is associated with weight loss ( 5.5 ) Cholinomimetics may cause bladder outflow obstructions ( 5.6 ) Cholinomimetics are believed to have some potential to cause generalized convulsions ( 5.7 ) Cholinesterase inhibitors should be prescribed with care to patients with a history of asthma or obstructive pulmonary disease ( 5.8 ) 5.1 Anesthesia Donepezil hydrochloride, as a cholinesterase inhibitor, is likely to exaggerate succinylcholine type muscle relaxation during anesthesia. 5.2 Cardiovascular Conditions Because of their pharmacological action, cholinesterase inhibitors may have vagotonic effects on the sinoatrial and atrioventricular nodes. This effect may manifest as bradycardia or heart block in patients both with and without known underlying cardiac conduction abnormalities. Syncopal episodes have been reported in association with the use of donepezil hydrochloride. 5.3 Nausea and Vomiting Donepezil hydrochloride, as a predictable consequence of its pharmacological properties, has been shown to produce diarrhea, nausea, and vomiting. These effects, when they occur, appear more frequently with the 10 mg/day dose than with the 5 mg/day dose, and more frequently with the 23 mg dose than with the 10 mg dose. Specifically, in a controlled trial that compared a dose of 23 mg/day to 10 mg/day in patients who had been treated with donepezil 10 mg/day for at least three months, the incidence of nausea in the 23 mg group was markedly greater than in the patients who continued on 10 mg/day (11.8% vs. […]
Reported side effects
Most common adverse reactions in clinical studies of donepezil hydrochloride are nausea, diarrhea, insomnia, vomiting, muscle cramps, fatigue, and anorexia ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Unichem Pharmaceuticals (USA) Inc. at 1-866-562-4616 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. The 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 )] 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. Donepezil hydrochloride 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. Controlled and uncontrolled trials in the United States included approximately 900 patients. In regards to the highest dose of 10 mg/day, this population includes 650 patients treated for 3 months, 475 patients treated for 6 months, and 116 patients treated for over 1 year. The range of patient exposure is from 1 to 1,214 days. Mild to Moderate Alzheimer's Disease Adverse Reactions Leading to Discontinuation The rates of discontinuation from controlled clinical trials of donepezil hydrochloride due to adverse reactions for the donepezil hydrochloride 5 mg/day treatment groups were comparable to those of placebo treatment groups at approximately 5%. The rate of discontinuation of patients who received 7-day escalations from 5 mg/day to 10 mg/day was higher at 13%. […]
Interactions with other medicines
Cholinesterase inhibitors have the potential to interfere with the activity of anticholinergic medications ( 7.1 ) A synergistic effect may be expected with concomitant administration of succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists ( 7.2 ) 7.1 Use with Anticholinergics Because of their mechanism of action, cholinesterase inhibitors have the potential to interfere with the activity of anticholinergic medications. 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.
Use in specific groups
Pregnancy: Based on animal data, may cause fetal harm ( 8.1 ) 8.1 Pregnancy Risk Summary There are no adequate data on the developmental risks associated with the use of donepezil hydrochloride in pregnant women. In animal studies, developmental toxicity was not observed when donepezil was administered to pregnant rats and rabbits during organogenesis, but administration to rats during the latter part of pregnancy and throughout lactation resulted in increased stillbirths and decreased offspring survival at clinically relevant doses [see Data]. In the U.S. general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies are 2% to 4% and 15% to 20%, respectively. The background risks of major birth defects and miscarriage for the indicated population are unknown. Data Animal Data Oral administration of donepezil to pregnant rats and rabbits during the period of organogenesis did not produce any teratogenic effects at doses up to 16 mg/kg/day (approximately 6 times the maximum recommended human dose [MRHD] of 23 mg/day on a mg/m 2 basis) and 10 mg/kg/day (approximately 7 times the MRHD on a mg/m 2 basis), respectively. Oral administration of donepezil (1, 3, 10 mg/kg/day) to rats during late gestation and throughout lactation to weaning produced an increase in stillbirths and reduced offspring survival through postpartum day 4 at the highest dose. The no-effect dose of 3 mg/kg/day is approximately equal to the MRHD on a mg/m 2 basis. 8.2 Lactation Risk Summary There are no data on the presence of donepezil or its metabolites in human milk, the effects on the breastfed infant, or on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for donepezil hydrochloride and any potential adverse effects on the breastfed infant from donepezil hydrochloride or from the underlying maternal condition. 8.4 Pediatric Use The safety and effectiveness in pediatric patients have not been established. 8.5 Geriatric Use Alzheimer's disease is a disorder occurring primarily in individuals over 55 years of age. […]
If too much is taken
Because strategies for the management of overdose are continually evolving, it is advisable to contact a Poison Control Center to determine the latest recommendations for the management of an overdose of any drug. As in any case of overdose, general supportive measures should be utilized. Overdosage with cholinesterase inhibitors can result in cholinergic crisis characterized by severe nausea, vomiting, salivation, sweating, bradycardia, hypotension, respiratory depression, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Tertiary anticholinergics such as atropine may be used as an antidote for donepezil hydrochloride overdosage. Intravenous atropine sulfate titrated to effect is recommended: an initial dose of 1.0 to 2.0 mg IV with subsequent doses based upon clinical response. Atypical responses in blood pressure and heart rate have been reported with other cholinomimetics when co-administered with quaternary anticholinergics such as glycopyrrolate. It is not known whether donepezil hydrochloride and/or its metabolites can be removed by dialysis (hemodialysis, peritoneal dialysis, or hemofiltration). Dose-related signs of toxicity in animals included reduced spontaneous movement, prone position, staggering gait, lacrimation, clonic convulsions, depressed respiration, salivation, miosis, tremors, fasciculation, and lower body surface temperature.
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This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 19 December 2025. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.