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Acetylcholinesterase inhibitor (AChEI) — dementia Pregnancy: Not applicable (used in elderly population).

Donepezil

Brand names: Aricept

Adult dose

Dose: 5 mg once daily for 4 weeks; increase to 10 mg once daily
Route: Oral
Frequency: Once daily (at bedtime to reduce nausea/insomnia)
Max: 10 mg/day
Alzheimer's disease (mild-severe): 5 mg at night for 4 weeks, increase to 10 mg. Also used off-label in Lewy body dementia and Parkinson's dementia. NICE TA217: licensed for all stages of AD. Discontinue if no benefit at maximum tolerated dose after 3–6 months.

Paediatric dose

Route: Not applicable
Frequency: Not licensed in children
Max: Not applicable
Not licensed in children.

Dose adjustments

Renal

No dose adjustment required.

Hepatic

No dose adjustment required for mild-moderate impairment; caution in severe.

Clinical pearls

  • Start at bedtime to minimise nausea — move to morning if insomnia or vivid dreams
  • Anticholinergic drugs negate AChEI benefit — anticholinergic burden review essential
  • Review adherence and response at 3 months; MMSE/MOCA change + carer report
  • Orodispersible tablets available for patients with swallowing difficulties
  • Carotid sinus hypersensitivity patients: higher syncope/bradycardia risk

Contraindications

  • Hypersensitivity to donepezil or piperidine derivatives
  • Sick sinus syndrome or supraventricular conduction defects

Side effects

  • GI upset (nausea, diarrhoea, vomiting — most common, especially on dose increase)
  • Bradycardia and syncope
  • Insomnia and vivid dreams (take at bedtime or switch to morning if persistent)
  • Muscle cramps
  • Agitation
  • Urinary incontinence

Interactions

  • Anticholinergic drugs (oxybutynin, antihistamines) — antagonistic (impair cognition and reduce donepezil efficacy)
  • SSRIs — additive serotonergic effects
  • NSAIDs — increased GI bleeding risk
  • Succinylcholine — prolonged neuromuscular blockade (AChEI effect)

Monitoring

  • MMSE/MoCA (every 6 months)
  • ECG (if cardiac disease or bradycardia)
  • HR
  • Weight

Reference: BNFc; BNF; NICE TA217 Dementia; NICE NG97 Dementia. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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