Acetylcholinesterase inhibitor (AChEI) — dementia Pregnancy: No adequate data in pregnant women; should not be used during pregnancy unless clearly necessary. Women on donepezil should not breast-feed.

Donepezil

Brand names: Aricept

Used in: Delirium & Cognitive Impairment

Donepezil is an acetylcholinesterase inhibitor used to treat the symptoms of Alzheimer's disease.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 5 mg once daily initially, increasing to 10 mg once daily

Route: Oral

Frequency: Once daily, in the evening just prior to retiring

Max: 10 mg/day (doses greater than 10 mg/day have not been studied in clinical trials)

Adults/elderly: treatment is initiated at 5 mg/day. The 5 mg/day dose should be maintained for at least one month to allow the earliest clinical responses to be assessed and steady-state concentrations to be achieved. After a one-month clinical assessment at 5 mg/day the dose can be increased to 10 mg/day. Treatment should be initiated and supervised by a physician experienced in the diagnosis and treatment of Alzheimer's dementia, and only started if a caregiver is available to monitor drug intake regularly. Reassess clinical benefit regularly; consider discontinuation when a therapeutic effect is no longer present. Orodispersible tablet: place on the tongue and allow to disintegrate before swallowing, with or without water. If sleep disturbance (abnormal dreams, nightmares, insomnia) occurs, morning intake may be considered. Not recommended for use in children and adolescents below 18 years of age. Hepatic impairment: due to possible increased exposure in mild to moderate impairment, dose escalation should follow individual tolerability; no data in severe hepatic impairment. CROSS-CHECK FLAG: the US label in the bundle permits up to 23 mg/day for moderate to severe Alzheimer's disease (after at least 3 months at 10 mg/day) — this is NOT in the UK SPC, which caps at 10 mg/day.

Dose adjustments

Renal

A similar dose schedule can be followed in renal impairment, as clearance of donepezil hydrochloride is not affected by this condition.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Mild to Moderate Alzheimer's Disease: 5 mg to 10 mg once daily ( 2.1 ) Moderate to Severe Alzheimer's Disease: 10 mg to 23 mg once daily ( 2.2 ) 2.1 Dosing in Mild to Moderate Alzheimer’s Disease The recommended starting dosage of donepezil hydrochloride tablet is 5 mg administered once per day in the evening, just prior to retiring. The maximum recommended dosage of donepezil hydrochloride tablets in patients with mild to moderate Alzheimer's disease is 10 mg per day. A dose of 10 mg should not be administered until patients have been on a daily dose of 5 mg for 4 to 6 weeks. 2.2 Dosing in Moderate to Severe Alzheimer’s Disease The recommended starting dosage of donepezil hydrochloride …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-11-29. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to donepezil hydrochloride, to piperidine derivatives, or to any of the excipients

Side effects

Diarrhoea, nausea and vomiting
Muscle cramps
Fatigue and headache
Insomnia, abnormal dreams and nightmares
Dizziness and syncope; bradycardia and sino-atrial/atrioventricular block

Interactions

Likely to exaggerate succinylcholine-type muscle relaxation during anaesthesia (cholinesterase inhibitor)
Synergistic effect expected with succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists such as bethanechol
Potential to interfere with the activity of anticholinergic medications
Caution with drugs affecting the QTc interval (post-marketing reports of QTc prolongation and Torsade de Pointes)
Concurrent NSAIDs increase ulcer risk — monitor for symptoms
Very rare neuroleptic malignant syndrome, particularly with concomitant antipsychotics

Clinical monograph

How it works

It inhibits acetylcholinesterase, increasing acetylcholine availability to support cognition; it eases symptoms rather than altering the underlying disease.

Prescribing in practice

Cholinergic effects (nausea, diarrhoea, bradycardia, syncope) occur — use caution in cardiac conduction problems, active peptic ulcer disease and significant airways disease.
It is usually taken at night.
Review benefit periodically.

Monitoring

Review cognition and function, heart rate and gastrointestinal tolerance; consider an ECG if bradycardia or syncope occurs.

Counselling the patient

Nausea or vivid dreams can occur and often settle.
Report fainting, a slow pulse, or significant weight loss.
It manages symptoms but does not cure the condition.

Evidence & guidelines

Recommended for Alzheimer's disease per NICE NG97/TA217.

Reference: NICE TA217 Dementia; NICE NG97 Dementia; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways