Estimates of plasma levels of Megestrol Acetate are dependent on the measurement method used. Peak plasma concentrations occur 2 to 3 hours after a single oral dose 160 mg tablets. The plasma half-life of Megestrol Acetate is 33 to 38 hours. Approximately 66% of an administered dose is excreted in the urine and approximately 20% in the faeces.

• Breast cancer: 160 mg/day
• Endometrial carcinoma: 40-320 mg/day in divided doses.
• At least 2 months of continuous treatment is considered an adequate period for determining the efficacy of Megestrol.

Thromboembolic Phenomena: Thromboembolic phenomena including thrombophlebitis and pulmonary embolism (in some cases fatal) have been reported.

Glucocorticoid Effects: The glucocorticoid activity of Megestrol Acetate has not been fully evaluated. Clinical cases of new onset diabetes mellitus, exacerbation of preexisting diabetes mellitus, and overt Cushing’s syndrome have been reported in association with the chronic use of Megestrol Acetate. In addition, clinical cases of adrenal insufficiency have been observed in patients receiving or being withdrawn from chronic Megestrol Acetate therapy in the stressed and non-stressed state.

Other: Nausea, dyspnea, tumor flare, hyperglycemia, glucose intolerance, alopecia, hypertension, carpal tunnel syndrome, mood changes, hot flashes, malaise, asthenia, lethargy, sweating and rash.

Use in Diabetics: Exacerbation of preexisting diabetes with increased insulin requirements has been reported in association with the use of Megestrol Acetate.

Geriatric Use: In the dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.