For an 80-year-old man with moderate dementia (SLUMS score 10), hypertension, iron-deficiency anemia, hyperlipidemia, currently taking losartan‑hydrochlorothiazide, atorvastatin, iron with vitamin C, and metoprolol succinate extended-release, who discontinued memantine because it made him mean, what medication can be started for his dementia besides referral to neurology?

Start a Cholinesterase Inhibitor

For this 80-year-old man with moderate dementia (SLUMS score 10) who discontinued memantine due to behavioral side effects, you should initiate a cholinesterase inhibitor—specifically donepezil, rivastigmine, or galantamine—as these are the appropriate first-line pharmacologic agents for his stage of dementia.

Clinical Context and Rationale

This patient has moderate dementia based on his SLUMS score of 10. Since memantine caused intolerable behavioral changes ("made him mean"), the next appropriate step is to start a cholinesterase inhibitor (ChEI), which represents standard pharmacologic management for Alzheimer's disease and related dementias at this stage 1.

Why Cholinesterase Inhibitors Are Appropriate

The 2020 Canadian Consensus Conference guidelines support the use of ChEIs for Alzheimer's disease, Parkinson's disease dementia, Lewy body dementia, and vascular dementia 2. These medications have demonstrated:

• Modest but meaningful benefits in cognition, function, and global assessment in moderate dementia 1
• Tolerability with manageable side effects (primarily gastrointestinal: nausea, vomiting, diarrhea) 1, 3
• Safety profile superior to older agents like tacrine 3

Specific Medication Recommendations

Choose based on tolerability, ease of use, and cost 1:

• Donepezil: Start 5 mg once daily, increase to 10 mg after 4-6 weeks if tolerated. Advantages include once-daily dosing and generally good tolerability
• Rivastigmine: Start 1.5 mg twice daily with food, titrate gradually. Available as a patch formulation which may improve tolerability
• Galantamine: Start 4 mg twice daily with food, titrate gradually to 8-12 mg twice daily

No evidence demonstrates superiority of one ChEI over another 1, so selection should prioritize practical factors and patient-specific considerations.

Important Clinical Considerations

Drug Interactions and Comorbidities

This patient's current medications require attention:

• Metoprolol succinate: ChEIs can cause bradycardia through vagotonic effects. His current beta-blocker increases this risk. Monitor heart rate closely, especially during titration 3
• Losartan-hydrochlorothiazide: No significant interaction expected
• Atorvastatin: No significant interaction
• Iron supplementation: Continue, as iron deficiency may independently affect cognitive function 4

Minimizing Side Effects

To reduce gastrointestinal side effects 3:

• Start at the lowest dose and titrate slowly (every 4-6 weeks)
• Administer with food
• Ensure adequate hydration
• Consider antiemetics if nausea develops

Monitoring and Follow-up

Assess response at 3 months 1:

• Look for improvement, stabilization, or decreased rate of decline
• If no benefit is observed, consider switching to a different ChEI
• Monitor for bradycardia, especially given concurrent beta-blocker use
• Assess for gastrointestinal side effects

When to Consider Discontinuation

Per 2020 Canadian guidelines 2, discontinuation should be considered if:

• Clinically meaningful worsening despite treatment over 6 months
• No benefit observed at any time during treatment
• Development of intolerable side effects
• Severe or end-stage dementia develops

Common Pitfalls to Avoid

1. Don't restart memantine immediately: He already failed this due to behavioral side effects. ChEIs are the appropriate next step
2. Don't overlook bradycardia risk: The combination of a ChEI with metoprolol requires cardiac monitoring
3. Don't expect dramatic improvement: Benefits are typically modest—stabilization or slowing of decline is a realistic goal 1
4. Don't discontinue prematurely: Allow at least 3 months to assess response before declaring treatment failure 1

Additional Considerations

Addressing His Iron Deficiency

Continue iron supplementation as planned. Emerging evidence suggests anemia and iron deficiency may independently affect cognitive function and could influence dementia biomarkers 4, 5.

Blood Pressure Management

His hypertension is controlled on current therapy. Maintaining good blood pressure control is important, as hypertension is a modifiable risk factor for cognitive decline 6, 7. Some evidence suggests renin-angiotensin system blockers (like his losartan) may have additional cognitive benefits 7.

Neurology Referral

While you appropriately plan neurology referral, initiating a ChEI in primary care is reasonable and should not be delayed pending specialty evaluation. The neurologist can refine the diagnosis and optimize management.

The evidence supports initiating a cholinesterase inhibitor now, with donepezil being the most practical choice given once-daily dosing, but any of the three first-line ChEIs (donepezil, rivastigmine, galantamine) would be appropriate 1, 3.