Megace has long been shown to help weight gain in cancer and AIDS. More recently, Megace ES came on the market. The advantage is in the concentrated dose that Megace ES offers. It is indicated for the treatment of anorexia, cachexia, or an unexplained, significant weight loss in patients with a diagnosis of acquired immunodeficiency syndrome (AIDS).

The recommended adult initial dosage of Megace ES (megestrol acetate) oral suspension is 625 mg/day (5 mL/day or one teaspoon daily). The equivalent Megace dose it 800 mg and requires 20 ml. These drugs are are bioequivalent in a fed state.
However,  in unfed patients Megace ES achieved 5 times greater peak plasma levels than Megace suspension. Additionally, the study demonstrated that a lower volume of Megace ES achieved maximum blood concentration more rapidly than the currently available oral suspension products.

However, the two products were not directly compared in regard to clinical effectiveness and it is not known if this pharmacokinetic advantages translate into any clinical advantage.

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The recommended adult initial dosage of Megace ES (megestrol acetate) oral suspension is 625 mg/day (5 mL/day or one teaspoon daily). The equicaletn Megace dose it 800 mg and requires 20 ml. Megace ES 625 mg/5 mL and megestrol acetate oral suspension 800 mg/20 mL are bioequivalent in a fed state.
A bioavailability study directly comparing the rate and extent of absorption of Megace ES and megestrol acetate oral suspension revealed that the Cmax** level with the original formulation was 1,364 ng/mL in fed patients and 187 ng/mL in unfed patients. In contrast, the Cmax level with Megace ES was 1,517 ng/mL in fed patients and 1,041 ng/mL in unfed patients. Further, in unfed patients Megace ES achieved 5 times greater peak plasma levels than megestrol acetate oral suspension. Additionally, the study demonstrated that a lower volume of Megace ES achieved maximum blood concentration more rapidly than the currently available oral suspension products.

However, the two products were nto directly compared in regard to clinical effectiveness and it is not known if this pharmacokinetic advantages translate into any clinical advantage.

Jamie H. Von Roenn, MD; Donald Armstrong, MD; Donald P. Kotler, MD; David L. Cohn, MD; Nancy G. Klimas, MD; N. S. Tchekmedyian, MD; Lawrence Cone, MD; Patrick J. Brennan, MD; and Sigmund A. Weitzman, MD, Megestrol Acetate in Patients with AIDS-related Cachexia , Ann Intern Med. 15 September 1994;121(6):393-399

Michelle H. Oster, PhD, RD; Sheila R. Enders, BS; Steven J. Samuels, PhD; Lawrence A. Cone, MD; Thomas M. Hooton, MD; Henry P. Browder, PhD; and Neil M. Flynn, MD
Megestrol Acetate in Patients with AIDS and Cachexia Ann Intern Med. 15 September 1994;121(6):400-408

Food Effect Working Group of the Biopharmaceutics Coordinating Committee, Office of Pharmaceutical Science. Guidance for industry: food-effect bioavailability and fed bioequivalence studies. Food and Drug Administration, Center for Drug Evaluation and Research Web site. http://www.fda.gov/cder/guidance/5194fnl.pdf. Published December 2002

MegaceES, Prescribing Information, 2013

Food and Drug Administration, Center for Drug Evaluation and Research. Electronic Orange Book: Approved Drug Products With Therapeutic Equivalence Evaluations. 28th ed. Rockville, MD: Food and Drug Administration, Center for Drug Evaluation and Research; 2008.

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