Pharmacokinetics of Pamidronate Disodium in Patients with Cancer with Normal or Impaired Renal Function

Abstract

Pamidronate is a second‐generation bisphosphonate that undergoes negligible biodegradation and is eliminated exclusively by renal excretions. Nineteen cancer patients were stratified according to baseline creatinine clearance (Cl_cr): group I, Cl_cr >90 mL/min (n = 6); group II, Cl_cr 61 mL/min to 90 mL/min (n = 6); group III, Cl_cr 30 mL/min to 60 mL/min (n = 3); group IV, Cl_cr 0–36) of 19.0 ± 4.60 μg·hr/mL compared with 8.1 ± 3.13 μg·hr/mL in patients in group I. A linear relationship in Cl_cr was observed for AUC_0–36 (r = 0.67), urinary excretion (r = 0.69), and renal clearance (r = 0.81). Renal clearance was proportional to Cl_cr for patients in all four renal‐function groups. In the treatment of bone metastases of malignancy, successive doses of pamidronate are generally separated by weeks; thus, plasma accumulation in patients with renal impairment is not expected to be clinically relevant. A reduction in dose of pamidronate disodium should not be necessary in cancer patients with renal impairment.