Medications for Appetite Stimulation
Megestrol acetate is the most effective medication for stimulating appetite, with strong evidence supporting its use at doses of 160-800 mg/day. 1
First-Line Options
Megestrol Acetate
- Dosage: 160-800 mg/day (optimal dose appears to be 480-800 mg/day)
- Evidence: High-quality evidence from multiple randomized controlled trials
- Benefits: Significant increase in appetite and body weight
- Mechanism: Synthetic progestogen
- Cautions: Monitor for thromboembolic events (RR 1.84), edema (RR 1.36), and adrenal suppression 1, 2
Corticosteroids
- Dosage: Variable depending on specific agent
- Evidence: Good quality evidence (level B1)
- Benefits: Rapid appetite stimulation, similar to megestrol acetate
- Limitations: Efficacy declines with long-term use; best for patients with limited life expectancy (weeks to months)
- Cautions: Muscle wasting, insulin resistance, infections 1
Second-Line Options
Mirtazapine
- Dosage: 15-30 mg once daily (preferably at bedtime)
- Benefits: Effective appetite stimulation, particularly useful for patients with concomitant depression or sleep difficulties
- Cautions: Sedation, dizziness 2
Dronabinol (Synthetic THC)
- Dosage: Initially 2.5 mg twice daily (one hour before lunch and dinner)
- Evidence: FDA-approved for AIDS-related anorexia
- Benefits: Statistically significant improvement in appetite
- Cautions: Neuropsychiatric effects (feeling high, dizziness, confusion, somnolence) in approximately 18% of patients
- Dosing adjustment: If side effects occur, reduce to 2.5 mg/day as a single dose at supper or bedtime 3
Medroxyprogesterone Acetate (MPA)
- Dosage: Minimum effective dose is 200 mg/day
- Evidence: Good quality evidence (level B1) for appetite stimulation
- Limitations: Effect on weight gain not well established 1
Medications with Limited Evidence
Olanzapine
- Limited but promising evidence for appetite stimulation in cancer cachexia
- Current guidelines do not recommend routine use due to insufficient clinical trials 1
Cyproheptadine
- May stimulate appetite but has reported adverse effects
- Limited evidence (level C) 1
Ineffective Medications
The following medications have not shown appetite-stimulating effects and should not be used for this purpose:
- Hydrazine sulfate
- Metoclopramide
- Nandrolone
- Pentoxifylline
- TNF inhibitors
- Insulin 1
Algorithm for Medication Selection
Assess underlying cause of decreased appetite (depression, GI disorders, pain, oral health issues)
First-line therapy:
- For cancer patients: Megestrol acetate (start at 160 mg/day, can increase to 480-800 mg/day if needed)
- For patients with depression: Consider mirtazapine 15 mg at bedtime
- For short-term use or end-of-life care: Consider corticosteroids
If first-line ineffective after 2-4 weeks:
- Switch to alternative first-line agent
- Consider second-line options like dronabinol
Monitor response:
- Weigh patient weekly
- Assess appetite improvement
- Evaluate for side effects (especially thromboembolic events with megestrol)
Important Considerations
- Combine pharmacological interventions with non-pharmacological approaches (small frequent meals, high-calorie foods, pleasant eating environment)
- Discontinue ineffective treatments rather than continuing indefinitely
- Monitor for side effects, particularly thromboembolic events with megestrol acetate
- The type of weight gain with megestrol acetate is primarily adipose tissue rather than skeletal muscle 1
- Early morning administration of dronabinol appears to be associated with increased adverse effects compared to dosing later in the day 3