Product Information

Registration Status: Active

APO-MEGESTROL TABLET 160mg is approved to be sold in Singapore with effective from 1998-05-10. It is marketed by PHARMAFORTE SINGAPORE PTE LTD, with the registration number of SIN10157P.

This product contains Megestrol Acetate 160mg in the form of TABLET. It is approved for ORAL use.

This product is manufactured by APOTEX INC in CANADA.

It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.

Megestrol Acetate


17-Hydroxy-6-methylpregna-3,6-diene-3,20-dione. A progestational hormone used most commonly as the acetate ester. As the acetate, it is more potent than progesterone both as a progestagen and as an ovulation inhibitor. It has also been used in the palliative treatment of breast cancer.


For the treatment of anorexia, cachexia, or an unexplained, significant weight loss in patients with a diagnosis of acquired immunodeficiency syndrome (AIDS). Also used for the palliative management of recurrent, inoperable, or metastatic breast cancer, endometrial cancer, and prostate cancer in Canada and some other countries.

Mechanism of Action

The precise mechanism by which megestrol acetate produces effects in anorexia and cachexia is unknown at the present time, but its progestin antitumour activity may involve suppression of luteinizing hormone by inhibition of pituitary function. Studies also suggest that the megestrol's weight gain effect is related to its appetite-stimulant or metabolic effects rather than its glucocorticoid-like effects or the production of edema. It has also been suggested that megestrol may alter metabolic pathyways via interferences with the production or action of mediators such as cachectin, a hormone that inhibits adipocyte lipogenic enzymes.


Variable, but well absorbed orally.
Primarily hepatic. Megestrol metabolites which were identified in urine constituted 5% to 8% of the dose administered. Respiratory excretion as labeled carbon dioxide and fat storage may have accounted for at least part of the radioactivity not found in urine and feces. No active metabolites have been identified.


No serious unexpected side effects have resulted from studies involving megestrol acetate oral suspension administered in dosages as high as 1200 mg/day. Treatment with megestrol acetate, an orexigenic agent, has also resulted in iatrogenic adrenal suppression. The mechanism is presumably related to the glucocorticoid properties of megestrol acetate [PMID: 12872362].

Active Ingredient/Synonyms

17-Acetoxy-6-methylpregna-4,6-diene-3,20-dione | 17-Hydroxy-6-methylpregna-4,6-diene-3,20-dione 17-acetate | 17alpha-Acetoxy-6-dehydro-6-methylprogesterone | 17alpha-Hydroxy-6-methylpregna-4,6-diene-3,20-dione acetate | 17α-Acetoxy-6-dehydro-6-methylprogesterone | 17α-Hydroxy-6-methylpregna-4,6-diene-3,20-dione acetate | 6-Dehydro-6-methyl-17alpha-acetoxyprogesterone | 6-Dehydro-6-methyl-17α-acetoxyprogesterone | 6-Methyl-17alpha-acetoxypregna-4,6-diene-3,20-dione | 6-Methyl-17alpha-hydroxy-delta(sup 6)-progesterone acetate | 6-Methyl-17α-acetoxypregna-4,6-diene-3,20-dione | 6-Methyl-17α-hydroxy-delta(sup 6)-progesterone acetate | 6-Methyl-6-dehydro-17alpha-acetoxyprogesterone | 6-Methyl-6-dehydro-17α-acetoxyprogesterone | 6-Methyl-delta(sup 4,6)-pregnadien-17alpha-ol-3,20-dione acetate | 6-Methyl-delta(sup 4,6)-pregnadien-17α-ol-3,20-dione acetate | 6-Methyl-delta(sup 6)-dehydro-17alpha-acetoxyprogesterone | 6-Methyl-delta(sup 6)-dehydro-17α-acetoxyprogesterone | MGA | Megestrol acetate |

Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank