Acetylcholinesterase inhibitor Pregnancy: Should not be used during pregnancy unless clearly necessary (§4.6). There are no adequate data from use in pregnant women; animal studies have not shown teratogenic effect but have shown pre- and post-natal toxicity, and the potential risk for humans is unknown. Breast-feeding: it is not known whether donepezil is excreted in human breast milk and there are no studies in lactating women — women on donepezil should not breast feed.

Donepezil hydrochloride

Brand names: Aricept

Used in: Delirium & Cognitive Impairment

Donepezil hydrochloride is a centrally acting reversible acetylcholinesterase inhibitor used to treat mild to moderately severe Alzheimer's disease dementia.

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, maintained for at least one month; following a one-month clinical assessment the dose can be increased to 10 mg once daily

Route: Oral — taken in the evening, just prior to retiring. Orodispersible tablet: place on the tongue and allow to disintegrate before swallowing, with or without water

Frequency: Once daily (once-a-day dosing)

Max: 10 mg per day — the maximum recommended daily dose. Doses greater than 10 mg/day have not been studied in clinical trials

Source: UK SPC (eMC) for Apozyl 10 mg Orodispersible Tablets, §4.2 (https://www.medicines.org.uk/emc/product/15539/smpc). The 5 mg/day dose should be maintained for at least one month in order to allow the earliest clinical responses to treatment to be assessed and to allow steady-state concentrations to be achieved. Treatment should be initiated and supervised by a physician experienced in the diagnosis and treatment of Alzheimer's dementia; diagnosis should be made according to accepted guidelines (e.g. DSM IV, ICD 10). Therapy should only be started if a caregiver is available who will regularly monitor drug intake for the patient. Maintenance treatment can be continued for as long as a therapeutic benefit exists; the clinical benefit should be reassessed on a regular basis and discontinuation considered when evidence of a therapeutic effect is no longer present. Individual response cannot be predicted. Upon discontinuation, a gradual abatement of the beneficial effects is seen. In case of sleep disturbances including abnormal dreams, nightmares or insomnia (§4.8), intake in the morning may be considered. HEPATIC IMPAIRMENT: due to possible increased exposure in mild to moderate hepatic impairment, dose escalation should be performed according to individual tolerability; there are no data for patients with severe hepatic impairment. PAEDIATRIC: not recommended for use in children and adolescents below 18 years of age (no per-kg dose is stated, hence paedDose is null) — verify any under-18 use against a children's formulary. The eMC bundle did not include §4.5, so the interactions listed below are taken from the US FDA label §7 (openFDA) — verify against the UK SPC §4.5.

Dose adjustments

Renal

A similar dose schedule can be followed for patients with renal impairment, as clearance of donepezil hydrochloride is not affected by this condition (§4.2).

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.

Contraindications

Hypersensitivity to donepezil hydrochloride, to piperidine derivatives, or to any of the excipients listed in section 6.1

Side effects

Diarrhoea, nausea and vomiting (the most common adverse events; diarrhoea and nausea are very common)
Muscle cramps and fatigue (common); rhabdomyolysis reported (rare), occurring independently of neuroleptic malignant syndrome and in close temporal association with initiation or dose increase
Insomnia, abnormal dreams and nightmares, hallucinations, agitation and aggressive behaviour (resolve on dose reduction or discontinuation)
Syncope, dizziness, headache; seizure (uncommon) — in patients with syncope or seizure consider the possibility of heart block or long sinusal pauses
Bradycardia (uncommon); sino-atrial block and atrioventricular block (rare); QT interval prolongation and polymorphic ventricular tachycardia including Torsade de Pointes (not known)
Liver dysfunction including hepatitis (rare) — in cases of unexplained liver dysfunction, withdrawal should be considered

Interactions

Anticholinergic medications — cholinesterase inhibitors have the potential to interfere with their activity (US label §7.1)
Succinylcholine, similar neuromuscular blocking agents, or cholinergic agonists such as bethanechol — a synergistic effect may be expected with concomitant administration (US label §7.2)

Clinical monograph

How it works

It reversibly inhibits acetylcholinesterase, increasing synaptic acetylcholine availability and partially compensating for the cholinergic deficit characteristic of Alzheimer's disease.

Prescribing in practice

Cholinergic effects can provoke bradycardia, heart block and syncope, so use caution in patients with sick sinus syndrome, conduction abnormalities or on rate-limiting drugs, and review susceptibility before starting.
Once-daily dosing is usually taken in the evening, and the dose is titrated upward after an initial period at the lower strength to improve tolerability.
Caution in peptic ulcer disease, asthma or chronic obstructive pulmonary disease, urinary outflow obstruction and in patients at risk of seizures.

Monitoring

Monitor cognitive and functional response, weight, heart rate and gastrointestinal tolerability, with cardiac assessment if syncope or significant bradycardia occurs.

Counselling the patient

Take the dose in the evening and report fainting, slow heartbeat, black stools or persistent nausea.
Benefit is symptomatic and the medicine does not cure or halt the underlying disease.
Tell other clinicians you take this drug before any anaesthetic or new heart medication.

Evidence & guidelines

NICE guidance on dementia recommends acetylcholinesterase inhibitors including donepezil as options for managing mild to moderate Alzheimer's disease.

Reference: NICE TA217; 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

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