Is Megestrol (megestrol acetate) safe to use in patients with Impaired renal function undergoing dialysis?

Megestrol Acetate Use in Dialysis Patients

Megestrol acetate can be used in dialysis patients at reduced doses (40-160 mg/day) with careful monitoring, as it is not significantly removed by dialysis and may cause side effects at higher doses. 1

Safety Profile in Renal Impairment

• Megestrol acetate is substantially excreted by the kidney, increasing risk of toxic reactions in patients with impaired renal function 1
• The FDA label specifically notes that megestrol acetate has not been tested for dialyzability, but due to its low solubility, dialysis is unlikely to be an effective means of treating overdose 1
• Higher doses (800 mg/day) used in initial studies showed significant side effects in dialysis patients, including diarrhea, confusion, hyperglycemia, headaches, and dizziness 2

Dosing Recommendations

• Lower doses of 40 mg/day (20 mg twice daily) have been shown to increase serum albumin levels in 75% of dialysis patients with malnutrition 3
• Moderate doses of 160 mg/day have demonstrated improvement in appetite and weight gain in peritoneal dialysis patients without significant side effects 4
• Doses of 400 mg/day (half the conventional dose) have been shown to be effective and relatively safe in improving nutritional status in dialysis patients 5
• High doses (800 mg/day) are likely too large for end-stage renal disease patients and carry increased risk 2

Clinical Benefits

• Megestrol acetate can help address malnutrition-inflammation complex syndrome, which is common in dialysis patients 5
• Studies have shown improvements in:
  • Appetite (reported in 68.8% of patients in one study) 4
  • Serum albumin levels (increase from 2.7 to 3.1 g/dL in responsive patients) 3
  • Body weight (statistically significant weight gain starting at 3 months) 4
  • Quality of life measures 5

Monitoring Requirements

• Regular monitoring of:
  • Serum albumin and other nutritional parameters 3
  • Body composition (as increases in weight may primarily represent fat mass rather than muscle mass) 6
  • Blood glucose levels, especially in diabetic patients 2
  • Liver function tests 2

Potential Side Effects and Cautions

• Potential side effects include:
  • Vaginal bleeding in women (particularly with underlying uterine conditions) 3
  • Hyperglycemia, especially concerning in diabetic patients 2
  • Confusion and dizziness at higher doses 2
  • Alterations in body composition (increased fat mass with potential decrease in fat-free mass) 6

Clinical Approach

1. Start with a low dose (40-160 mg/day) in dialysis patients with malnutrition 3, 4
2. Monitor nutritional parameters, including serum albumin, weight, and appetite 5
3. Continue treatment if positive response is observed (typically within 1-3 months) 3, 4
4. Discontinue if side effects develop or no improvement is seen after an adequate trial period 2
5. Consider body composition assessment when available, as weight gain may primarily represent increased fat mass 6