What is the best appetite stimulant for elderly patients with moderate to severe protein-calorie malnutrition?

Best Appetite Stimulants for Elderly Patients with Moderate to Severe Protein-Calorie Malnutrition

Mirtazapine (7.5-15 mg at bedtime) is recommended as the first-line pharmacological appetite stimulant for elderly patients with moderate to severe protein-calorie malnutrition. 1

First-Line Approach: Nutritional Support

Before considering pharmacological interventions, optimize nutritional support:

• Offer oral nutritional supplements (ONS) providing at least 400 kcal/day including 30g or more of protein/day when dietary counseling and food fortification are insufficient 2
• Continue ONS for at least one month with regular assessment of efficacy 2
• Provide texture-modified, enriched foods for patients with chewing or swallowing problems 2
• Offer additional snacks and finger foods to facilitate dietary intake 2
• Create a relaxed, comfortable environment during meals with social interaction to stimulate appetite 3

Pharmacological Interventions

When non-pharmacological approaches are insufficient, consider the following medications:

First-Line:

• Mirtazapine (7.5-15 mg at bedtime)
  • Addresses both appetite stimulation and potential underlying depression 1
  • Side effects include increased appetite and weight gain (beneficial in this context), but also somnolence 4
  • Use lower starting doses in elderly patients with close monitoring 3

Second-Line:

• Megestrol acetate (400-800 mg/day)
  • Consider if mirtazapine is ineffective or contraindicated 1, 3
  • Associated with improved appetite in approximately 25% of patients 3
  • Important caution: Associated with higher risk of death (RR 1.42) and thromboembolic events (RR 1.84) compared to placebo 5
  • Weight gain is primarily adipose tissue rather than skeletal muscle 5
  • Regular assessment for thromboembolic phenomena is essential 5

Third-Line (for shorter life expectancy):

• Dexamethasone (2-8 mg/day)
  • Faster onset of action, suitable for patients with shorter life expectancy 1, 3
  • Significant side effects with prolonged use including hyperglycemia, muscle wasting, and immunosuppression 3

Implementation Strategy

1. Assessment:

   • Screen for malnutrition within 24 hours of hospital admission 6
   • Evaluate for treatable causes of poor appetite 1
   • Review medications that may contribute to poor appetite 1

2. Initial Intervention:

   • Begin with non-pharmacological approaches (ONS, food fortification, social interventions) 2
   • Provide at least 30 kcal/kg/day and 1 g/kg/day of protein 2
   • Adapt type, flavor, texture, and time of consumption to patient preferences 2

3. Escalation:

   • If insufficient response to non-pharmacological approaches after 2 weeks, add mirtazapine 1
   • Monitor for side effects, particularly sedation 4
   • If ineffective after 2-4 weeks, consider switching to megestrol acetate with careful risk assessment 1, 5

4. Monitoring:

   • Assess weight, appetite, and nutritional intake weekly 2
   • Monitor for medication side effects 1, 5
   • Evaluate for thromboembolic phenomena if using megestrol acetate 5

Special Considerations

• Dementia: Avoid appetite stimulants in patients with dementia without evidence of depression 1, 3
• End of Life: Focus on comfort and quality of life rather than nutritional goals 1
• Hospitalized Patients: ONS can improve dietary intake and body weight, and lower risk of complications and readmission 2
• Post-Discharge: Continue ONS after hospital discharge to improve dietary intake and body weight, and lower risk of functional decline 2

Clinical Pearls

• Malnutrition in elderly patients can lead to muscle atrophy, sarcopenia, impaired immune function, and increased morbidity and mortality 7
• Loss of appetite is often part of "sickness behavior" triggered by inflammatory signals 7
• Protein supplementation may transiently depress hunger but doesn't necessarily reduce overall food intake in mildly undernourished elderly 8
• Correction of malnutrition can improve immune and hematopoietic abnormalities in elderly patients 9
• Reasonable nutritional management requires qualified staff in adequate numbers to allow appropriate individual nutritional care 10