Appetite Stimulants for Patients with Loss of Appetite
Megestrol acetate (400-800 mg/day) is the most effective first-line pharmacological appetite stimulant for patients with decreased appetite, improving appetite in approximately 25% of patients and promoting modest weight gain in about 8% of patients. 1
First-Line Pharmacological Options
- Megestrol acetate (400-800 mg/day) is recommended as the most effective first-line appetite stimulant, with the minimum effective dose being 160 mg/day and no additional benefit seen with doses above 480 mg/day 1, 2
- Dexamethasone (2-8 mg/day) offers a faster onset of action, making it more suitable for patients with shorter life expectancy or when rapid appetite improvement is needed 1, 3
- Mirtazapine (7.5-30 mg at bedtime) is particularly effective for patients with concurrent depression and appetite loss, with studies showing mean weight gain of 1.9 kg after three months 1, 4
- Olanzapine (5 mg/day) may be considered for patients with concurrent nausea/vomiting 1, 4
Special Population Considerations
Cancer Patients
- Both megestrol acetate and corticosteroids (e.g., dexamethasone) are recommended for anorexia/cachexia related to cancer 3, 2
- For patients with cancer cachexia, combination therapy approaches may yield better outcomes than single agents 3
Patients with AIDS
- Dronabinol (starting at 2.5 mg before lunch and dinner, may be reduced to 2.5 mg once daily at supper or bedtime) has FDA approval for appetite stimulation in AIDS-related anorexia with weight loss 5
- Dronabinol showed statistically significant improvement in appetite compared to placebo at 4 and 6 weeks in AIDS patients 5
Elderly Patients
- Lower starting doses should be used with close monitoring for side effects, particularly sedation and thromboembolic events 1, 2
- For patients with dementia, pharmacological appetite stimulants are NOT recommended due to limited evidence and potential risks 1
Non-Pharmacological Approaches
- Provide oral nutritional supplements when food intake is between 50-75% of usual intake 1
- Serve energy-dense meals to help meet nutritional requirements without increasing meal volume 1
- Offer protein-enriched foods and drinks to improve protein intake 1
- Create a relaxed, comfortable environment during meals with emotional support and supervision 1
- Place patients at dining tables rather than isolated in rooms to promote social interaction during meals 1
- Ensure consistent caregivers during meals when possible 1
Important Monitoring and Precautions
- Regular reassessment is essential to evaluate benefit versus harm of pharmacological interventions 1, 4
- Monitor for side effects of megestrol acetate, including fluid retention and increased risk of thromboembolic events (affects approximately 1 in 6 patients) 3, 1
- Be aware that dexamethasone has significant side effects with prolonged use, including hyperglycemia, muscle wasting, and immunosuppression 1
- For dronabinol, monitor for side effects such as feeling high, dizziness, confusion, and somnolence, which occurred in 18% of patients at higher doses 5
Treatment Algorithm
- Assess underlying cause of appetite loss and treat reversible causes (e.g., oropharyngeal candidiasis, depression, early satiety) 3
- Implement non-pharmacological approaches first, including nutritional support strategies and environmental modifications 1
- Select appropriate pharmacological agent based on:
- Start with lower doses in elderly patients and titrate as needed 1, 2
- Monitor regularly for effectiveness and adverse effects 1
Despite the widespread use of appetite stimulants in hospitalized patients, recent evidence suggests limited efficacy on improving appetite and meal intake in the inpatient setting, highlighting the need for careful patient selection 6.