Expansion
Cholinesterase inhibitors first, memantine second
Expansion
Acetylcholinesterase inhibitors: donepezil, rivastigmine, galantamine
- For mild to moderate Alzheimer’s, and also in Lewy body and Parkinson’s disease dementia, where they are particularly effective for hallucinations
- Side effects are cholinergic: nausea, diarrhoea, bradycardia, syncope, insomnia, muscle cramps. Caution with bradycardia and heart block
Memantine, an NMDA receptor antagonist
- For moderate to severe Alzheimer’s, in intolerance of cholinesterase inhibitors, or added to them
- Better tolerated, with dizziness and headache
Neither is effective in vascular dementia, where treatment is vascular risk factor control.
Drugs to avoid
- Antipsychotics, which increase stroke and mortality in dementia. Reserve for severe distress or risk, at the lowest dose for the shortest time
- In Lewy body dementia, antipsychotics can cause severe neuroleptic sensitivity, with marked parkinsonism, autonomic instability and death
- Anticholinergics, which worsen cognition and directly oppose the cholinesterase inhibitors. Review the total anticholinergic burden
- Benzodiazepines and other sedatives
Non-drug measures come first for behavioural symptoms: identify pain, infection, constipation, sensory impairment, boredom and environmental triggers before prescribing.