From the Guidelines
Megace (megestrol acetate) should be dosed at 400-800 mg daily for appetite stimulation and weight gain in patients with cancer cachexia or AIDS-related wasting. The optimal dose is between 480 and 800 mg per day, as suggested by a review of 29 trials using progestins in a total of 4139 cancer patients 1. For hormone-responsive cancers like breast or endometrial cancer, the dose is usually 40-320 mg daily. Treatment should begin with 400 mg daily for appetite stimulation, which can be adjusted based on response. The medication comes as an oral suspension (40 mg/ml) or tablets (20, 40, or 160 mg).
Key Points to Consider
- Megace works by stimulating appetite through multiple mechanisms, including antagonizing the effects of pro-inflammatory cytokines and modulating neuropeptide Y in the hypothalamus.
- Side effects may include thromboembolic events, adrenal suppression, hyperglycemia, and fluid retention.
- Patients should be monitored for weight gain, appetite improvement, and potential adverse effects.
- The medication typically takes 1-3 weeks to show appetite improvement, and treatment duration varies based on the clinical indication and patient response.
Evidence-Based Recommendations
A recent Cochrane review on megestrol acetate for treatment of the anorexia-cachexia syndrome analysed 35 trials comprising 3963 patients and concluded that this drug showed a benefit compared with placebo with regard to appetite and weight but resulted in higher rates of oedema, thromboembolic phenomena, and deaths 1. Another study published in the Journal of the National Comprehensive Cancer Network also supports the use of megestrol acetate for appetite stimulation and weight gain in patients with cancer cachexia 2.
From the FDA Drug Label
The recommended adult initial dosage of megestrol acetate oral suspension, USP is 800 mg/day (20 mL/day). In clinical trials evaluating different dose schedules, daily doses of 400 and 800 mg/day were found to be clinically effective. The recommended dose of Megace is 800 mg/day.
- The effective dose range is between 400 mg/day and 800 mg/day 3.
From the Research
Megace Dose Information
- The dose of Megestrol acetate varied across different studies, with some studies using a dose of 80 mg four times daily 4, while others used higher doses such as 320 mg/day 5, 400 mg/day 6, 160 mg/day 7, or 320 mg/day 7.
- A study comparing two different doses of megestrol acetate (160 mg/day and 320 mg/day) found that the higher dose was more effective in producing weight gain in patients with advanced non-small cell lung cancer 7.
- Another study found that a moderate dose of 400 mg/day was effective in improving the nutritional state and inflammation in maintenance dialysis patients 6.
- High-dose megestrol acetate (up to 640 mg/day) was also used in some studies, with one study finding that it was effective in producing weight gain in patients with HIV-related cachexia 4.
- However, a meta-analysis of 23 clinical trials found that megestrol acetate did not appear to be effective in providing symptomatic improvement of anorexia/cachexia in patients with advanced cancer, regardless of the dose used 5.
Dosage and Efficacy
- The efficacy of megestrol acetate in producing weight gain and improving appetite varied across different studies, with some studies finding significant improvements 4, 6, 7 and others finding no significant effects 5.
- The time to peak weight gain also varied across studies, with one study finding that the median time to peak weight was 14 weeks 4.
- The safety and tolerability of megestrol acetate also varied across studies, with some studies reporting no major side effects 6 and others reporting thromboembolic events and other adverse effects 5.
Clinical Applications
- Megestrol acetate has been used in various clinical settings, including the treatment of anorexia and cachexia associated with HIV infection 4, cancer 5, 7, and maintenance dialysis 6.
- The use of megestrol acetate in these settings is often off-label, and further research is needed to fully understand its efficacy and safety in these populations.