Donepezil (Aricept) 💊
Related Subjects:
|Dementias
|Abbreviated Mental Test Score (AMTS)
|Alzheimer disease
|Dementia with Lewy bodies
|Frontotemporal dementia
|Corticobasal degeneration
|Creutzfeldt Jakob disease
|Vascular Dementia
|Primary progressive aphasia
|Anti Dementia Drugs
|AIDS Dementia Complex
|Normal Pressure Hydrocephalus
|Acetylcholinesterase inhibitors
|Mental Capacity Act 2005
|Behavioural and Psychological Symptoms of Dementia
💡 Cholinesterase inhibitors like Donepezil do not prevent disease progression, but they may temporarily improve or stabilise symptoms.
Always follow BNF guidance and local protocols. Liaise with Geriatricians, Psychogeriatricians, or Neurologists before starting.
⚠️ Side effects are significant, so initiation must be carefully considered.
⚙️ Mode of Action
- Acetylcholinesterase inhibitor (AChEI) → prevents breakdown of acetylcholine
- Increases cholinergic transmission at muscarinic & nicotinic receptors
- Aims to improve cognition and function in dementia
📌 Indications
- Mild to moderately severe Alzheimer’s disease
- Dementia with Lewy bodies
- Parkinson’s disease dementia
- Vascular or mixed dementia (select cases)
💊 Dosing – Donepezil (check BNF)
| Regimen |
Details |
| 🌙 Starting dose |
• 5 mg PO once daily at night
|
| ⬆️ Maintenance |
• Increase to 10 mg PO once daily
• Only after ≥4 weeks at starting dose, if tolerated
|
🔄 Interactions
- Metabolised by CYP450 → affected by enzyme inducers and inhibitors
- Inducers (↓ effect): Phenytoin, Carbamazepine
- Inhibitors (↑ effect/toxicity): Erythromycin, Paroxetine, Fluoxetine
🚫 Contraindications
- Hypersensitivity to donepezil or piperidine derivatives (no other absolute contraindications).
⚠️ Cautions
- Sick sinus syndrome or other supraventricular conduction defects (bradycardia, heart block).
- Asthma or COPD (bronchoconstriction).
- Monitor for falls
- If pulse <50 bpm: stop donepezil and any concurrent beta-blocker, obtain ECG
- Use cautiously in extrapyramidal disease and peptic ulcer disease
🔄 Alternatives if Not Tolerated
- Switch to another AChEI (e.g., Rivastigmine, Galantamine)
- Consider Memantine as an alternative
💥 Side Effects
- Very common: diarrhoea, nausea, headache.
- Common: vomiting, anorexia, muscle cramps, fatigue, insomnia and vivid dreams (give in the morning if troublesome), dizziness, syncope, urinary incontinence, rash, pruritus, common cold.
- Uncommon: bradycardia, seizures, GI haemorrhage, peptic ulcer.
- Rare: sino-atrial and AV block, extrapyramidal symptoms, hepatic dysfunction, rhabdomyolysis, neuroleptic malignant syndrome; QT prolongation and torsade de pointes have been reported.
🧪 Monitoring
- Pulse at baseline and at each review; ECG if there is bradycardia, syncope, conduction disease or QT-prolonging co-medication.
- Weight and appetite.
- Review benefit and tolerability at about 3 months, then regularly; stop if there is no benefit or adverse effects outweigh benefit.
📚 References
