What medications can be initiated in primary care for dementia?

Medications for Dementia in Primary Care

Cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are the first-line medications that can be initiated in primary care for mild to moderate dementia, with memantine recommended for moderate to severe dementia. 1, 2

First-Line Medications for Dementia

Donepezil (Aricept)

• Initial dosage of 5 mg once daily, which can be increased to 10 mg once daily after 4 weeks if tolerated 1
• Provides moderate improvement in cognitive function and global assessment in mild to moderate Alzheimer's disease 1
• Side effects include mild gastrointestinal issues (nausea, vomiting, diarrhea) and potential temporary increase in agitation during first few weeks 1
• Once-daily dosing makes it convenient for patients 3, 4
• No hepatotoxicity concerns, unlike tacrine 5

Rivastigmine (Exelon)

• Initial dosage of 1.5 mg twice daily with food, increased by 1.5 mg twice daily every 4 weeks to maximum of 6 mg twice daily (12 mg/day) 1, 6
• Indicated for mild-to-moderate dementia of Alzheimer's type and Parkinson's disease dementia 6
• More gastrointestinal side effects than donepezil, including nausea, vomiting, diarrhea, and weight loss 1
• Take with food to reduce gastrointestinal side effects 1

Galantamine (Reminyl)

• Initial dosage of 4 mg twice daily with meals for 4 weeks, then increased to 8 mg twice daily for at least 4 weeks, with potential increase to 12 mg twice daily based on individual response 1
• Effective for improving cognitive and functional outcomes in mild to moderate Alzheimer's disease 1
• Side effects include nausea, vomiting, and diarrhea; taking with food can reduce these effects 1
• Contraindicated in patients with hepatic or renal impairment 1

Second-Line Medication

Memantine

• Recommended for moderate to severe Alzheimer's disease 1, 2
• Can be used as monotherapy or in combination with a cholinesterase inhibitor 2
• Dosage typically 20 mg/day 1
• Side effects include confusion, dizziness, and falls 2

Clinical Decision-Making Algorithm

1. Determine dementia type and severity:

   • Mild to moderate Alzheimer's disease → Start with cholinesterase inhibitor 1
   • Moderate to severe Alzheimer's disease → Consider memantine or combination therapy 1, 2
   • Parkinson's disease dementia → Consider rivastigmine 6
   • Vascular dementia → Consider cholinesterase inhibitor 1, 2

2. Select specific medication based on:

   • Patient characteristics (renal/hepatic function, weight) 6
   • Side effect profile concerns (more GI issues with rivastigmine) 1
   • Dosing convenience (once daily for donepezil vs. twice daily for others) 1
   • Comorbidities (avoid galantamine in hepatic/renal impairment) 1

3. Start with lowest dose and titrate gradually:

   • Donepezil: 5 mg daily for 4 weeks, then 10 mg daily 1
   • Rivastigmine: 1.5 mg twice daily, increase by 1.5 mg twice daily every 4 weeks 6
   • Galantamine: 4 mg twice daily for 4 weeks, then 8 mg twice daily 1

Monitoring and Follow-up

• Assess effectiveness by monitoring cognition, function, and neuropsychiatric symptoms 2
• Evaluate for side effects, particularly gastrointestinal issues 1
• Consider discontinuation after 12 months if no observed benefit or clinically meaningful worsening despite treatment 2

Important Considerations and Pitfalls

• Benefits of these medications are typically modest; set realistic expectations with patients and caregivers 1, 2
• Tacrine is no longer considered first-line treatment due to hepatotoxicity concerns 1
• Non-pharmacological interventions should always accompany medication therapy 2
• Avoid cholinesterase inhibitors for frontotemporal dementia 2
• If discontinuation is necessary, taper gradually rather than stopping abruptly 2
• Consider patient's weight, as lower-weight patients may experience more side effects 6

By following this approach, primary care providers can appropriately initiate and manage pharmacological treatment for patients with dementia, while monitoring for effectiveness and adverse effects.