Safety of In-hospital Parenteral Antiosteoporosis Therapy Following a Hip Fracture: A Retrospective Cohort

Abstract

Purpose: To assess the safety of zoledronic acid (ZOL) and denosumab (Dmab) administered following hip fracture in a hospital setting.

Methods: Patients older than 65 years were treated by a fracture liaison service following hip fracture. Generally, patients who had a glomerular filtration rate (eGFR) > 35 mL/min were treated with ZOL, whereas patients who had previously received bisphosphonates or had a eGFR between 20 and 35 mL/min were treated with Dmab. Adverse events included hypocalcemia (calcium corrected for albumin less than 8.5 mg/day), renal functional impairment (0.5 mg/dL or more increase in serum creatinine) within 30 days of treatment, or a fever (>38 °C) within 48 hours of drug administration.

Results: Two hundred twenty-eight and 134 patients were treated with ZOL and Dmab, respectively. Mean body temperature was elevated following ZOL administration (0.18 °C P < .001) but remained below 38 °C. Hypocalcemia occurred in 18% and 29% of the ZOL and Dmab groups, respectively (P = .009). Renal functional impairment was observed in 9 and 6 patients (4% and 5%) in the ZOL and Dmab groups, respectively (P = .8). Pretreatment calcium above 9.3 mg/dL was associated with a lower risk of posttreatment hypocalcemia (odds ratio 0.30, 95% confidence interval 0.13-0.68, P = .004). While the absolute risk of hypocalcemia was higher in the Dmab group, multivariate analysis did not find that the choice of drug was predictive of hypocalcemia.

Conclusion: In-hospital parenteral osteoporosis treatment was rarely associated with fever or renal function impairment but was associated with hypocalcemia. Posttreatment hypocalcemia risk did not vary significantly between patients receiving ZOL or Dmab.

Keywords: adverse effects; denosumab; hip fracture; osteoporosis; zoledronic acid.