We have studied pharmacokinetics of a new H2-receptor antagonist, TZU-0460, in patients with varying degrees of renal impairment. The apparent volume of distribution at steady-state was 1.70 l/kg, and the plasma protein binding of TZU-0460 or its active metabolite, desacetyl TZU-0460 was less than 10% in normal subjects. These variables were not altered with renal impairment. Sixty percent of TZU-0460 given orally was excreted via the kidney, mainly by tubular secretion. The half-time of elimination was 3.94 h in normal subjects, and was prolonged to 12.13 h in severe renal failure (creatinine clearance below 30 ml/min/1.48 m2). Dosage adjustment of TZU-0460 is necessary in renal failure.