Bisphosphonate nephrotoxicity.

Bisphosphonates are valuable agents for the treatment of post-menopausal osteoporosis (PMO), hypercalcemia of malignancy, and osteolytic bone metastases. Oral bisphosphonates are used mainly to treat PMO and are not associated with significant nephrotoxicity. In contrast, nephrotoxicity is a significant potential limiting factor to the use of intravenous (IV) bisphosphonates, and the nephrotoxicity is both dose-dependent and infusion time-dependent. The two main IV bisphosphonates available to treat hypercalcemia of malignancy and osteolytic bone disease in the United States are zoledronate and pamidronate. Patterns of nephrotoxicity described with these agents include toxic acute tubular necrosis and collapsing focal segmental glomerulosclerosis, respectively. With both of these agents, severe nephrotoxicity can be largely avoided by stringent adherence to guidelines for monitoring serum creatinine prior to each treatment, temporarily withholding therapy in the setting of renal insufficiency, and adjusting doses in patients with pre-existing chronic kidney disease. In patients with PMO, zoledronate and pamidronate are associated with significantly less nephrotoxicity, which undoubtedly relates to the lower doses and longer dosing intervals employed for this indication. Ibandronate is approved in the US for treatment of PMO and in Europe for treatment of PMO and malignancy-associated bone disease. Available data suggest that ibandronate has a safe renal profile without evidence of nephrotoxicity, even in patients with abnormal baseline kidney function.