Oral bisphosphonate use in the elderly is not associated with acute kidney injury

Intravenous bisphosphonates can cause acute kidney injury; however, this risk was not found with oral bisphosphonates in randomized clinical trials with restrictive eligibility criteria. In order to provide complementary safety data, we studied the risk of acute kidney injury in a population-based cohort of 122,727 patients aged 66 years and older discharged from hospital following a new fragility fracture and no history of bisphosphonate use in the prior year. Bisphosphonate treatment was identified within 120 days after discharge and event rates were measured from 90 days of therapy initiation. The primary outcome was hospitalization with acute kidney injury with secondary outcomes of new nephrology consultation and, in a subset of patients with laboratory values, acute kidney injury was defined as an increase in serum creatinine. We identified 18,286 bisphosphonate users and 104,441 non-users with a mean age of 81 years. Of 5772 patients with laboratory values, 40% had chronic kidney disease (eGFR <60 ml/min per 1.73 m2). Overall, there was no statistically significant difference in the risk of acute kidney injury among bisphosphonate users compared to non-users (adjusted odds ratio 1.03), and no significant differences in other outcomes or in subgroups of patients with baseline chronic kidney disease. Thus, in this older population-based cohort, oral bisphosphonate use was not associated with acute kidney injury.