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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Cholinesterase inhibitors and memantine principles

Psychiatry · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
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Collapse or toxicity requires urgent medicine review

Syncope, marked bradycardia, new conduction disturbance, severe vomiting or dehydration, gastrointestinal bleeding, seizure, severe confusion, repeated patch exposure or suspected overdose requires urgent physiological assessment and cessation advice from an appropriate prescriber or toxicology service.

Action: Assess ABCDE, pulse, blood pressure, glucose and ECG; identify every formulation, strength, dose and last administration; remove all rivastigmine patches if duplication is possible; correct immediate complications; and seek urgent medicines, poison-information or acute medical support. Do not restart or retitrate until the event and indication have been reviewed.

Synopsis

Match cognitive medicines to dementia subtype and stage, initiate and titrate using a safe supported regimen, measure benefit beyond a test score, and avoid inappropriate withholding, continuation or withdrawal.

  • Donepezil, galantamine and rivastigmine are acetylcholinesterase inhibitors; memantine is an NMDA-receptor antagonist with different indications and adverse effects.
  • NICE recommends any of the three AChE inhibitors as options for mild-to-moderate Alzheimer's disease, selecting by adverse effects, interactions, adherence and acquisition cost.
  • For Alzheimer's disease, offer memantine alone for moderate disease when AChE inhibitors are not tolerated or contraindicated, or for severe disease.
  • For a person already taking an AChE inhibitor, consider adding memantine in moderate Alzheimer's disease and offer addition in severe disease.
  • For mild-to-moderate dementia with Lewy bodies, offer donepezil or rivastigmine; consider galantamine only when both are not tolerated, and consider memantine when AChE inhibitors cannot be used. These DLB uses are off-label.
  • Only consider these medicines in vascular dementia when comorbid Alzheimer's, Parkinson's disease dementia or DLB is suspected; do not offer them for frontotemporal dementia.
  • Do not stop an AChE inhibitor solely because Alzheimer's disease has become severe; review actual benefit, tolerability, goals and administration feasibility.
  • Before treatment document subtype, stage, cognition, function, behaviour, pulse, weight, comorbidity, interactions and who will support administration.
  • Titrate one change at a time and reassess adverse effects and meaningful function; apparent worsening may reflect delirium, non-adherence or an interrupted regimen.
  • Cognitive medicines are symptomatic, not curative; continue non-drug support, advance planning, sensory care, physical health treatment and carer support.

    • Key red flags

    Syncope, pulse slowing, new dizziness on standing or an ECG conduction abnormality may represent clinically important cholinergic cardiac toxicity.

    Persistent vomiting, diarrhoea, anorexia or weight loss can cause dehydration and disproportionate frailty during cholinesterase-inhibitor treatment.

    More than one rivastigmine patch applied at once can produce serious overdose; remove old patches before every new application.

    Haematemesis, melaena or acute abdominal pain raises concern for gastrointestinal ulceration or bleeding, particularly with NSAIDs or prior ulcer disease.

    New rigidity, hallucinations, acute inattention or reduced consciousness needs assessment for delirium, medicine effects and intercurrent illness rather than automatic dose escalation.

    A rapid functional decline, seizure or focal neurology should reopen the diagnosis and trigger appropriate acute or specialist assessment.

    Investigation priorities

    01
    Subtype and stage reviewFirst step

    Confirm that the dementia formulation and current severity support the proposed medicine or combination.

    Management branches

    Treatment selectionMatch medicine to subtype and stage

    A confirmed dementia diagnosis prompts consideration of symptomatic cognitive treatment.

    1. Confirm subtype, stage, current medicines, contraindications, administration support and the person's informed goals.
    2. Apply NICE Alzheimer's, Lewy-body, vascular or frontotemporal recommendations rather than treating all dementia identically.
    3. Choose formulation and agent using adverse effects, interactions, adherence, medical comorbidity, dose profile and acquisition cost.

    Key medicines

    DonepezilStart 5 mg by mouth once daily and continue for at least one month; after clinical review, increase if appropriate to 10 mg once daily, which is the recommended maximum.Review bradycardia, syncope, conduction disease, QT risk, ulcer or gastrointestinal bleeding, asthma or COPD, seizures, weight loss and interacting rate-limiting or anticholinergic medicines.
    Galantamine prolonged-releaseStart 8 mg by mouth once daily for 4 weeks, then 16 mg once daily for at least 4 weeks; consider 24 mg once daily only after individual assessment of clinical benefit and tolerability.Give with food and adequate fluids as product-directed; review renal and hepatic impairment, bradycardia, syncope, gastrointestinal symptoms, weight loss, ulcer risk and CYP-mediated interactions.
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    Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
    Sources

    Sources and review status

    National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

    • NICE NG97 dementia recommendationsSubtype- and stage-specific AChE-inhibitor and memantine indications, combination use, selection and continuation principles.
    • Donepezil 5 mg SmPCUK licensed indication, 5 mg initiation, one-month review, 10 mg maximum and medicine-specific safety information.
    • Galantamine prolonged-release SmPCCurrent 8 mg, 16 mg and individually assessed 24 mg regimen and monitoring requirements.
    • Rivastigmine transdermal patch SmPCPatch strengths, titration, application, interruption, low-weight caution and adverse-effect management.
    • Memantine 20 mg SmPCCurrent weekly titration, maintenance, renal-dose thresholds, contraindications and adverse effects.

    Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

    Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom