What are the treatment options for appetite stimulants in patients with loss of appetite?

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 producing 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 pharmacological appetite stimulant, with the minimum effective dose being 160 mg/day and no evidence of increased efficacy above 480 mg/day 1, 2
• Dexamethasone (2-8 mg/day) offers a faster onset of action, making it suitable for patients with shorter life expectancy or when rapid appetite stimulation is needed 1, 3
• Mirtazapine (7.5-30 mg at bedtime) is particularly effective for patients with concurrent depression and appetite loss 1, 4
• Olanzapine (5 mg/day) may be considered for patients with concurrent nausea/vomiting 1, 4

Special Population Considerations

For Patients with Cancer

• Both megestrol acetate and corticosteroids are recommended for cancer-related anorexia/cachexia 3, 2
• A combination therapy approach may yield better outcomes, including regimens with medroxyprogesterone, megestrol acetate, eicosapentaenoic acid, L-carnitine supplementation, and thalidomide 3

For 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 AIDS-related anorexia with demonstrated efficacy in improving appetite 5

For Patients with Depression

• Mirtazapine is the preferred option, with studies showing weight gain of approximately 2 kg after 3-6 months of treatment 4
• Avoid bupropion as it promotes weight loss 4

For Elderly Patients

• Start with lower doses and monitor closely 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, 2
• Focus on non-pharmacological approaches instead 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
• Place patients at dining tables rather than isolated in rooms to promote social interaction during meals 1
• Provide emotional support, supervision, verbal prompting, and encouragement during mealtimes 1
• Ensure consistent caregivers during meals when possible 1
• Make snacks available between meals 1

Important Caveats and Side Effects

• Megestrol acetate: Risk of thromboembolic events (1 in 6 patients), fluid retention, and increased mortality (1 in 23 patients) 3, 1
• Dexamethasone: Significant side effects with prolonged use including hyperglycemia, muscle wasting, and immunosuppression 1
• Dronabinol: Side effects include feeling high, dizziness, confusion, and somnolence (occurring in 18% of patients at higher doses) 5
• Regular reassessment is essential to evaluate benefit versus harm of all pharmacological interventions 1

Efficacy in Hospital Settings

• Limited evidence exists for the efficacy of appetite stimulants in hospitalized patients 6
• A small retrospective study showed numerical improvements in meal intake (average 17.12% increase) with dronabinol, megestrol, or mirtazapine, with no significant differences between agents 7
• Almost half (48%) of hospitalized patients experienced improvement in diet after starting appetite stimulants 7

Remember that appetite loss may be a protective physiological response in some acutely ill patients, so the risks and benefits of appetite stimulation should be carefully weighed 8.