Effect of renal function on risedronate pharmacokinetics after a single oral dose

Aims To determine the relationship between risedronate pharmacokinetics and renal function. Methods Risedronate was administered to adult men and women (n=21) with various degrees of renal function (creatinine clearance 15–126 ml min−1 ) as a single oral dose of 30 mg. Serum samples were obtained for 72 h after dosing, and urine samples were collected for 72 h after dosing and then periodically for 6 weeks. Risedronate concentrations were determined using an enzyme‐linked immunosorbent assay (ELISA). Risedronate serum concentration‐time and urinary excretion rate‐time profiles were analysed simultaneously using nonlinear regression. Results Renal clearance and volume of distribution were linearly related to creatinine clearance (r2=0.854, P