Syndrome and subtype #
Separate subjective cognitive concern, objective impairment with preserved independence, and dementia affecting daily independence. Describe the predominant memory, language, executive, visuospatial or behavioural syndrome and the trajectory; then investigate its likely cause. Mixed pathology is possible.
Focused assessment #
Obtain the patient’s history and a collateral account of medication management, finances, cooking, navigation and personal care. Document onset, progression, neurological symptoms, alcohol exposure, sleep and mood. Examine cognition, behaviour, gait and neurological function. Interpret test performance in the context of language, education, hearing and vision.
Distinguishing clinical patterns #
| Pattern | Diagnostic direction |
|---|---|
| Progressive episodic-memory difficulty | Consider Alzheimer disease; corroborate functional change. |
| Executive impairment, focal signs or stroke relationship | Consider vascular contribution; correlate with imaging. |
| Fluctuation, visual hallucinations and parkinsonism | Consider Lewy body disease; review medication sensitivity. |
| Early personality, behaviour or language change | Consider frontotemporal degeneration and specialist assessment. |
| Rapid change, inattention or altered awareness | Investigate delirium, systemic illness and medication effects urgently. |
Investigations linked to decisions #
Use a tiered work-up rather than assuming all cognitive decline is degenerative. Structural imaging and laboratory findings contribute to the formulation; neither replaces history and examination.
| Assessment | Purpose |
|---|---|
| Blood count, renal/liver function, glucose, thyroid function, B12/folate as appropriate | Identify metabolic, endocrine, haematological or nutritional contributors. |
| MRI brain, or CT where MRI is unsuitable | Evaluate structural lesions, vascular disease and regional atrophy. |
| Neuropsychological assessment | Clarify subtle or atypical deficits when brief testing is inconclusive. |
| Specialist biomarkers or additional neurological investigations | Use when diagnostic uncertainty would change management; select for the clinical syndrome. |
Subtype-specific management #
For Alzheimer disease, NICE supports acetylcholinesterase inhibitors in mild–moderate disease; memantine is an option in severe disease, or moderate disease when these drugs are contraindicated or not tolerated. Adding memantine is considered in moderate and offered in severe disease already treated with an acetylcholinesterase inhibitor. Do not extend this automatically to isolated vascular or frontotemporal dementia.
Offer individualized activity, cognitive stimulation and functional support. New distress requires assessment of pain, illness, environment and unmet needs before psychotropic escalation.
Doses & prescribing #
Each prescribing record identifies its population and source jurisdiction; international labeling does not establish Indian approval. The clinician selects treatment after assessment.
Donepezil
Mild–moderate Alzheimer dementia
Adults · Conventional tablet · Oral · US label; treatment positioning also informed by UK NICE
- Starting dose
- 5 mg once daily in the evening.
- Titration
- Consider 10 mg/day only after 4–6 weeks at 5 mg/day, if tolerated.
- Treatment range / target
- 5–10 mg once daily.
- Maximum / limits
- 10 mg/day for this indication. The separate 23 mg regimen for moderate–severe disease is not represented here.
- Trial & duration
- Continue according to benefit and tolerability; reassess rather than using a fixed course.
- Monitoring
- Pulse, syncope, weight, gastrointestinal tolerance and bleeding symptoms.
- Population & organ-function adjustments
- Individualize for frailty and interacting medicines; no fixed geriatric reduction is specified here.
- Important cautions
- Bradycardia/heart block, peptic-ulcer risk, asthma/COPD, anticholinergic antagonism.
Memantine
Moderate–severe Alzheimer dementia
Adults · Immediate-release tablet · Oral · US label; UK NICE treatment positioning
- Starting dose
- 5 mg once daily.
- Titration
- At intervals of at least 1 week: 5 mg twice daily, then 5 mg morning/10 mg evening, then 10 mg twice daily.
- Treatment range / target
- Target 20 mg/day in divided doses when tolerated.
- Maximum / limits
- 20 mg/day for this formulation; severe renal impairment target 10 mg/day.
- Trial & duration
- Reassess continuing clinical usefulness; after several missed days, lower-dose restarting and retitration may be required.
- Monitoring
- Renal function, dizziness, confusion, constipation and functional response.
- Population & organ-function adjustments
- Creatinine clearance 5–29 mL/min: target 5 mg twice daily. Use caution in severe hepatic impairment.
- Important cautions
- Urine alkalinization can reduce clearance. Check other NMDA antagonists. Do not double a missed dose.
Deterioration during treatment #
Recheck the diagnosis, actual administration and adverse effects. Acute decline needs a new medical assessment rather than automatic dose escalation. Track cognition alongside function and collateral observations; decline does not by itself prove that a symptomatic medicine has no benefit.
Continuation and care planning #
Do not stop an acetylcholinesterase inhibitor solely because Alzheimer disease has become severe. Review the balance of benefit, adverse effects and practical administration. Advance planning should address future support, decision-making and changing care needs.
Frailty and medical comorbidity #
With donepezil, assess syncope, bradycardia, conduction disease, weight loss and gastrointestinal symptoms; concomitant anticholinergics can oppose its action. Memantine dosing depends on renal function, and severe hepatic impairment requires caution. Do not substitute the extended-release memantine schedule for the immediate-release table below.
What to review #
Compare cognitive domains and everyday function against baseline. Ask the caregiver about new difficulties and their own support needs. Review falls, nutrition, medication administration and adverse effects; record who will arrange additional assessment when change occurs.
Clinical pitfalls #
A normal brief score can miss clinically important decline in a highly educated patient. Conversely, limited literacy, sensory impairment or testing in an unfamiliar language can depress scores. Arrange specialist assessment when the history and test result do not agree.
Assessment tools #
Choose the instrument for its intended purpose; interpretation accompanies the linked tool.
Patient discussion #
Open a plain-language explanation
A memory score is one part of assessment. Changes in daily activities and information from someone who knows the person are equally important.
References · 6
- NICE NG97: Dementia recommendations · United Kingdom · Checked 2026-10-26 · Supports: Subtype-specific management; Deterioration during treatment; Continuation and care planning; What to review; Donepezil — Mild–moderate Alzheimer dementia (Conventional tablet); Memantine — Moderate–severe Alzheimer dementia (Immediate-release tablet)
- NINDS: Dementias—clinical features and diagnosis · United States · Checked 2026-10-26 · Supports: Syndrome and subtype; Distinguishing clinical patterns
- NHS: Tests for diagnosing dementia · United Kingdom · Checked 2026-10-26 · Supports: Focused assessment; Investigations linked to decisions; Deterioration during treatment; Clinical pitfalls
- Alzheimer’s Association DETeCD-ADRD diagnostic guideline · United States · Checked 2026-10-26 · Supports: Focused assessment; Investigations linked to decisions; What to review; Clinical pitfalls
- DailyMed: Donepezil conventional tablets, sections 2 and 5 · United States label · Checked 2026-10-26 · Supports: Frailty and medical comorbidity; Donepezil — Mild–moderate Alzheimer dementia (Conventional tablet)
- DailyMed: Memantine immediate-release tablets · United States label · Checked 2026-10-26 · Supports: Frailty and medical comorbidity; Memantine — Moderate–severe Alzheimer dementia (Immediate-release tablet)