What is the recommended dosage of Megestrol (megestrol acetate) for appetite stimulation?

Recommended Dosage of Megestrol Acetate for Appetite Stimulation

The recommended dosage of megestrol acetate for appetite stimulation is 400-800 mg/day orally. 1, 2, 3

Dosing Guidelines

Standard Dosing

• Initial dose: 800 mg/day (20 mL/day) as per FDA labeling 3
• Effective range: 400-800 mg/day has been clinically effective in trials 1, 2, 3
• Administration: Shake container well before using 3
• Duration: Consider discontinuation if ineffective after 4 weeks 2

Alternative Dosing Approaches

• Low-dose option: 80 mg twice daily (160 mg/day) after meals may be an appropriate starting dose for some cancer patients 4
• Moderate-dose option: 400 mg/day has shown effectiveness in improving nutritional status and reducing inflammation in dialysis patients 5
• Dose adjustment: Can start with 400 mg/day and increase to 800 mg/day if needed for optimal response 6

Monitoring and Expected Outcomes

Benefits

• Increased appetite (primary benefit)
• Weight gain (primarily through increased body fat)
• Improved quality of life
• Potential reduction in inflammatory markers 2, 5

Side Effects to Monitor

• Thromboembolic events (relative risk 1.84) 2
• Edema/fluid retention (relative risk 1.36) 2
• Adrenal suppression: Morning cortisol levels may decrease below normal limits (8 ng/mL)
  • At 400 mg: 70% of patients affected
  • At 800 mg: 78% of patients affected 7
• Increased mortality risk (relative risk 1.42) 2

Clinical Application Algorithm

1. Assess patient's condition:

   • Confirm anorexia/cachexia related to cancer, AIDS, or other chronic conditions
   • Evaluate life expectancy (months-to-weeks or weeks-to-days)
   • Determine if increased appetite is important for quality of life 1, 2

2. Select appropriate dosage:

   • For most patients: Start with 800 mg/day 3
   • For frail elderly or those at high risk of side effects: Consider 400 mg/day 5, 7
   • For patients with severe cachexia: 800 mg/day may be more effective 1, 2

3. Monitor effectiveness:

   • Assess appetite improvement within 2-4 weeks
   • Measure weight changes
   • Monitor nutritional markers (prealbumin may increase in a dose-dependent manner) 7

4. Adjust as needed:

   • If ineffective after 4 weeks: Consider discontinuation 2
   • If partial response: Consider dose escalation (up to 800 mg/day) 4
   • If side effects occur: Consider dose reduction

Important Caveats

• Megestrol acetate primarily increases body fat rather than lean body mass 6
• Consider combining with exercise programs and/or anabolic agents if preservation of lean body mass is important 6
• Monitor for thromboembolic events, especially in high-risk patients 2
• Adrenal suppression is common at higher doses and may persist even after discontinuation 7
• Effectiveness may be enhanced when combined with non-pharmacological approaches (small frequent meals, high-calorie foods, pleasant eating environment) 2