What is the recommended dose and safety profile of famotidine (histamine-2 receptor antagonist) in a patient with end-stage renal disease (Impaired renal function) on dialysis?

Famotidine Dosing in End-Stage Renal Disease on Dialysis

For patients with end-stage renal disease on dialysis, famotidine should be dosed at 20 mg every other day, administered after the dialysis session on dialysis days to prevent premature removal of the drug. 1

Pharmacokinetics in Renal Failure

• Famotidine elimination half-life is significantly prolonged (27.2 ± 8.5 hours) in patients with end-stage renal disease compared to normal renal function (2.6-3.6 hours) 2
• The drug's volume of distribution remains relatively unchanged in renal failure at approximately 1.3 L/kg 2
• Total body clearance is significantly reduced to about 33.5 ml/min in patients with end-stage renal disease 2
• Various dialysis modalities remove famotidine to different degrees:
  • Hemodialysis with polysulphone membranes: 16.4% of administered dose 2
  • Hemodialysis with cuprophan membranes: 6.0% of administered dose 2
  • Continuous hemofiltration: 16.2% over 24 hours 2
  • CAPD: 4.5% over 24 hours 2

FDA-Approved Dosing Recommendations

• For patients with creatinine clearance less than 30 mL/minute (which includes dialysis patients), the FDA recommends:
  • For active duodenal ulcer: 20 mg every other day 1
  • For active gastric ulcer: 20 mg every other day 1
  • For symptomatic non-erosive GERD: 20 mg every other day 1
  • For erosive esophagitis: 20 mg every other day 1
  • For pathological hypersecretory conditions: Avoid use 1

Administration Considerations

• Medications for dialysis patients should be administered after the dialysis session to prevent premature removal of the drug 3
• Famotidine may be taken with or without food 1
• Famotidine may be given with antacids if needed 1

Safety Profile

• Famotidine is generally well-tolerated in patients with renal impairment 4
• Unlike cimetidine, famotidine does not inhibit renal tubular secretion of creatinine, making it safer for monitoring renal function 5
• Famotidine does not require dose adjustment in patients with mild renal insufficiency, but dose reduction is necessary in severe renal impairment to avoid accumulation 4
• The drug is essentially free of dose-related adverse effects, but appropriate dosing is still important to prevent potential undesirable effects from accumulation 4

Common Pitfalls to Avoid

• Do not administer famotidine before dialysis sessions as this would lead to premature removal of the drug and subtherapeutic levels 3
• Do not use standard dosing in dialysis patients as it can lead to drug accumulation and potential toxicity 3
• For patients with fluctuating renal function, reassess frequently to adjust dosing as needed 6
• Pay special attention to elderly dialysis patients who may have further decreased drug clearance due to age-related changes 6, 4

Monitoring Recommendations

• Assess renal function periodically during treatment 6
• Monitor for signs of adverse effects, although famotidine has a favorable safety profile even in renal impairment 4
• Consider consulting with nephrology or clinical pharmacy for complex cases 7