๐ก Note: Clinical trials suggest that cholinesterase inhibitors may provide modest benefits in mild-to-moderate Alzheimerโs disease, dementia with Lewy bodies, vascular dementia, or mixed dementia. They can help with cognition, function, and behaviour but are not disease-modifying.
๐ About
Always check the BNF link here before prescribing.
- ๐ Rivastigmine is an acetylcholinesterase inhibitor (ChEI).
- ๐ง Increases central acetylcholine levels โ enhances cholinergic neurotransmission.
- Used primarily in dementia syndromes.
โ๏ธ Mode of Action
- Inhibits acetylcholinesterase and butyrylcholinesterase enzymes.
- Reduces breakdown of acetylcholine โ improves cholinergic signalling in the cortex and hippocampus.
๐ Indications
- ๐ง Alzheimerโs dementia (mild to moderate severity).
- ๐งฉ Parkinsonโs disease dementia (preferred agent due to lower EPS risk).
- ๐ญ Sometimes used in Lewy body dementia (off-label, specialist advice).
๐ Dose
- PO: 1.5 mg BD โ titrate every 2โ4 weeks up to 3โ6 mg BD (max tolerated dose).
- Transdermal patch: 4.6 mg/24 h โ may increase to 9.5 mg/24 h (improves GI tolerability).
- Always start low and titrate slowly to reduce GI side effects.
๐ Interactions
- See BNF for full list.
- โ ๏ธ Additive bradycardia with ฮฒ-blockers, digoxin, or amiodarone.
- โ ๏ธ May worsen bronchospasm in asthma/COPD patients on ฮฒโ-agonists.
โ Contraindications / Cautions
- โค๏ธ Heart block, sick sinus syndrome, bradycardia.
- ๐ซ Asthma or COPD โ risk of bronchospasm.
- ๐ง History of seizures โ may lower seizure threshold.
- ๐ป Bladder outflow obstruction.
- Monitor weight in frail/elderly patients.
โ ๏ธ Side Effects
- ๐ง Cholinergic symptoms โ โDUMBELSโ mnemonic: Diarrhoea, Urination, Miosis, Bronchospasm, Emesis (vomiting), Lacrimation/salivation, Sweating.
- โค๏ธ Bradycardia, hypotension, syncope, โ falls risk.
- ๐ง Headache, dizziness, insomnia, fatigue.
- ๐ฝ๏ธ GI: nausea, vomiting, anorexia, weight loss.
- ๐ช Muscle cramps.
๐ Clinical Pearls
- Start at the lowest dose and titrate every 2โ4 weeks based on tolerance.
- Transdermal patch often better tolerated than oral forms (fewer GI side effects).
- Monitor weight, blood pressure, and pulse regularly.
- Falls risk is increased โ counsel carers and patients.
- Stop if no meaningful benefit after 6 months or if side effects outweigh gains.
๐ References
