What is the recommended dose of Megace (megestrol acetate) and what evidence-based precautions should be taken when administering it?

From the Guidelines

Megace (megestrol acetate) should be prescribed at doses of 400-800 mg daily for appetite stimulation and weight gain in patients with conditions like cancer cachexia or AIDS-related wasting, with careful monitoring for potential side effects and consideration of combination therapy for optimal outcomes. The medication works by stimulating appetite through multiple mechanisms, including antagonism of tumor necrosis factor and modulation of calcium channels involved in feeding behavior 1. When using Megace, be watchful for potential side effects including blood clots (deep vein thrombosis or pulmonary embolism), fluid retention, hyperglycemia, adrenal suppression, and breakthrough vaginal bleeding. Patients with diabetes should monitor blood glucose levels closely as Megace can worsen glycemic control. Those with a history of thromboembolism should be particularly cautious. The medication typically takes 1-3 weeks to show effects on appetite and weight. For optimal results, patients should take Megace consistently with food and combine it with nutritional counseling. Regular monitoring of weight, blood glucose, and symptoms of fluid retention is recommended during treatment. Discontinuation should be gradual to prevent adrenal insufficiency, especially after long-term use.

Some key points to consider when prescribing Megace include:

• The use of combination therapy, which may yield the best possible outcomes for patients with cancer cachexia 1
• The potential benefits and risks of Megace in different patient populations, such as those with dementia 1
• The importance of careful monitoring and gradual discontinuation to prevent adverse effects 1
• The need for nutritional counseling and support to optimize outcomes 1

Overall, the use of Megace should be individualized and based on a careful consideration of the potential benefits and risks, as well as the latest evidence and guidelines 1.

From the FDA Drug Label

The recommended adult initial dosage of megestrol acetate oral suspension, USP is 800 mg/day (20 mL/day). Therapy with megestrol acetate oral suspension for weight loss should only be instituted after treatable causes of weight loss are sought and addressed. Use with caution in patients with a history of thromboembolic disease. Exacerbation of pre-existing diabetes with increased insulin requirements has been reported in association with the use of megestrol acetate Megestrol acetate may interact with warfarin and increase International Normalized Ratio (INR). Long-term treatment with megestrol acetate may increase the risk of respiratory infections

The recommended dose of Megace is 800 mg/day. When using Megace, be watchful for:

• Thromboembolic events in patients with a history of the condition
• Exacerbation of diabetes with increased insulin requirements
• Interactions with warfarin, which may increase International Normalized Ratio (INR)
• Respiratory infections with long-term treatment
• Breakthrough bleeding in female patients 2
• Adverse effects on the newborn, and nursing should be discontinued if megestrol acetate oral suspension is required 2

From the Research

Megace Dose and Evidence

The dose of Megace (megestrol acetate) varies depending on the patient's condition and response to treatment.

• In a study published in 1990, patients with HIV-related cachexia were treated with oral megestrol acetate at a dose of 80 mg four times daily, with some patients requiring higher doses of up to 640 mg per day 3.
• A 1993 study compared the efficacy of four different doses of megestrol acetate (160,480,800, and 1,280 mg/d) in patients with cancer anorexia and/or cachexia, and found that there was a positive dose-response effect for appetite stimulation 4.
• However, the study also suggested that the lowest dose of 160 mg/d may be sufficient for initial treatment of cancer anorexia/cachexia in routine clinical practice 4.

Adverse Effects to Watch For

When using Megace, clinicians should be aware of potential adverse effects, including:

• Adrenal insufficiency, which has been reported in some patients taking megestrol acetate 5.
• Mild edema, which was observed in some patients in a controlled trial of megestrol acetate for cancer anorexia and cachexia 6.
• Deep vein thrombosis, which was reported in one patient in a study of megestrol acetate for HIV-related cachexia 3.
• Clinicians should monitor patients for these potential adverse effects and adjust the dose or discontinue treatment as needed.