Megace (Megestrol Acetate) Dosing with Meals
The recommended adult initial dosage of megestrol acetate oral suspension is 800 mg/day (20 mL/day), which can be taken with meals to improve tolerability, though it is not required to be taken with food. 1
Dosing Recommendations
- The FDA-approved standard dose for megestrol acetate oral suspension is 800 mg/day (20 mL/day), which has been clinically effective in trials evaluating different dose schedules 1
- For the nanocrystal formulation (Megace ES), a more concentrated version, the dose is 625 mg/5 mL once daily, which provides equivalent efficacy with a smaller volume 2
- Lower doses of 400 mg/day have also shown clinical effectiveness in improving nutritional status and reducing inflammation in certain patient populations 3
- Some clinicians use an even lower dose of 80 mg twice daily after meals (160 mg/day total) as an appropriate starting dose for anorexia in advanced cancer, with the option to increase if ineffective 4
Administration with Meals
- While the FDA label does not specifically require taking megestrol acetate with meals, clinical practice often includes administration with meals to improve tolerability 1
- The nanocrystal formulation (Megace ES) has improved bioavailability in the fasting state compared to the conventional micronized formulation, making it less dependent on food intake 5
- For the conventional micronized formulation (Megace OS), food significantly increases bioavailability, with systemic exposure being 1.9-fold higher in the fed state versus fasting 5
Dosing Considerations
- Dose-response studies have shown a positive correlation between higher doses and appetite stimulation, though even lower doses (160 mg/day) can be effective 6
- For patients who experience gastrointestinal side effects, dividing the daily dose and taking it with meals (e.g., 400 mg twice daily with breakfast and dinner) may improve tolerability 7
- The optimal dose range for appetite stimulation has been suggested to be between 480 and 800 mg per day 7
Side Effects and Monitoring
- Common side effects include edema, thromboembolic phenomena, and impotence 7
- Weight gain from megestrol acetate is primarily due to increased fat mass rather than lean body mass 7
- Patients should be monitored for potential serious side effects such as thromboembolism, especially at higher doses 7
Special Populations
- In patients with severe renal impairment, no specific dose adjustments are recommended in the FDA labeling, but clinical monitoring is advised 1
- For elderly patients who may be more prone to dehydration, careful monitoring is recommended when initiating therapy 7
By following these dosing recommendations, megestrol acetate can effectively stimulate appetite and promote weight gain in patients with anorexia and cachexia associated with cancer and other conditions.