Brand Names of Megestrol Acetate
Megestrol acetate is marketed under the brand names Megace (original oral suspension formulation) and Megace ES (enhanced nanocrystal dispersion formulation). 1, 2
Available Formulations
Megace Oral Suspension (Megace OS)
- The original formulation contains 800 mg/20 mL and has been marketed since July 2001 for anorexia, cachexia, and AIDS-related weight loss 1, 2
- This micronized formulation was originally developed by Bristol-Myers Squibb, with generic versions subsequently manufactured by Par Pharmaceutical and other companies 1, 2
Megace ES (Enhanced Suspension)
- This advanced nanocrystal dispersion (NCD) formulation contains 625 mg/5 mL, representing a more concentrated form 1, 2
- FDA approved in July 2005 for treatment of anorexia, cachexia, or unexplained weight loss in AIDS patients 1, 2
- Patients take only a teaspoon (5 mL) once daily compared to a 20 mL dosage cup of the original formulation 1, 2
Key Formulation Differences
Bioavailability Advantages of Megace ES
- The nanocrystal formulation demonstrates significantly improved bioavailability in the fasting state, with peak plasma concentration 6.7-fold higher and area under the curve 1.9-fold higher compared to the original Megace OS 3
- In fasting subjects, the maximum concentration for Megace ES was only 30% less than fed state values, whereas Megace OS showed 86% reduction in fasting versus fed states 4
- This reduced food effect makes Megace ES particularly advantageous for cachectic patients with reduced caloric intake 4, 3
Clinical Implications
- Both formulations show comparable absorption when taken with food 4, 3
- The liquid suspension formulation is preferred over tablets as it is less expensive and more bioavailable 5
- Megace ES may be the preferred formulation when managing patients whose caloric intake is reduced, as systemic exposure is less affected by lack of concomitant food intake 4, 3