Synopsis
Recognise the older-adult Alzheimer phenotype, establish functional and collateral evidence with appropriate imaging and specialist diagnosis, use cognitive medicines safely within licence and NICE guidance, and coordinate autonomy, carers and progressive support.
- Typical Alzheimer disease begins insidiously with impaired learning and retention of new episodic information, then affects orientation, language, visuospatial and executive function.
- Diagnosis combines progressive cognitive change, interference with function, collateral evidence, examination, exclusion of delirium and contributors and structural imaging.
- MRI commonly shows medial temporal and later generalised atrophy but imaging supports rather than proves the diagnosis.
- Specialist CSF or amyloid biomarkers are reserved for meaningful diagnostic uncertainty; APOE testing is not a routine diagnostic test.
- First-line cognitive treatment for mild-to-moderate Alzheimer disease is one acetylcholinesterase inhibitor: donepezil, galantamine or rivastigmine.
- Memantine is recommended for moderate disease when AChE inhibitors are unsuitable or not tolerated, and for severe Alzheimer disease; combination may be considered with established AChE treatment.
- Donepezil commonly starts 5 mg once daily and may increase to 10 mg after at least one month if tolerated; check pulse, weight, GI and interaction risk.
- Memantine begins 5 mg daily and increases by 5 mg each week to 20 mg daily, with renal dose adjustment.
- Do not stop a cognitive medicine solely because severity has increased; review benefit, adverse effects, adherence and the person's goals.
- Pair medicine with activity, communication, sensory, vascular, nutrition, safety, advance-planning and carer support; no tablet replaces coordinated care.
Key red flags
Hours-to-days change, marked fluctuation or altered arousal suggests delirium superimposed on Alzheimer disease.
Rapid progression, early focal signs, seizure, gait or continence syndrome and severe headache requires an alternative neurological search.
Syncope, bradycardia, falls, weight loss, vomiting or gastrointestinal bleeding after a cholinesterase inhibitor requires urgent medicine review.
Getting lost, fire, medication errors, scams or unsafe driving needs immediate proportionate risk management and capacity assessment.
Suicide intent, severe depression, psychosis or carer violence and exhaustion requires same-day mental-health or safeguarding action.
Do not interpret increasing help as proof that every decision-making capacity is lost; assess each decision with support.
Acute inattention or altered arousal represents new physiological illness, not an overnight Alzheimer stage change.
Syncope, pulse slowing, weight loss or GI symptoms after titration may reflect cholinesterase inhibition.
Investigation priorities
Establish the progressive amnestic phenotype.
Management branches
An insidious amnestic and functional decline is reported.
- Exclude delirium and modifiable contributors and obtain detailed collateral with accessible cognitive testing.
- Complete examination, standard blood work and structural imaging and assess mixed pathology.
- Refer for specialist diagnosis, medicine eligibility, counselling, capacity and support planning.
Mild-to-moderate Alzheimer disease is diagnosed and treatment is consistent with goals.
- Check pulse, conduction and syncope, weight, GI and respiratory history, interactions and administration support.
- Start the selected licensed agent at its initial dose and titrate only after tolerance and target review.
- Monitor cognition, daily function, adverse effects and carer observation and continue only while net benefit remains reasonable.