Famotidine is a H2-antagonist indicated for the treatment of peptic ulcers, Zollinger-Ellison Syndrome and gastrointestinal reflux. It is available in the oral and parenteral form.

The previous labelling recommended dosage adjustments for severe renal insufficiency only (creatinine clearance < 10 ml/min). Recent data have identified the need for dosage adjustments in patients with moderate renal insufficiency (creatinine clearance < 50 ml/min). This is because the drug is substantially excreted by the kidney and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. There is a close relationship between creatinine clearance and the elimination half-life of famotidine. Since CNS side effects have been reported in patients with moderate and severe renal insufficiency, to avoid excess accumulation of the drug in insufficiency, the dose of famotidine may be reduced to half the dose or the dosing interval may be prolonged to 36 - 48 hours (instead of 24 hours) as indicated by the patient's clinical response.

Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.