Hypocalcemia in Children with Osteogenesis Imperfecta Treated with Intravenous Zoledronic Acid

Abstract

Background: Bisphosphonates (Pamidronate and Zoledronic acid) mainly used for the treatment of childhood osteoporosis such as osteogenesis imperfecta have been associated with adverse effects ranging from acute phase response, hypocalcemia, musculoskeletal pain and up to serious side effects such as osteonecrosis of the jaw. In this report, we describe the prevalence of hypocalcemia among Saudi children treated with Zoledronic acid. Method: The biochemical profile of 13 Saudi children with osteogenesis imperfecta treated with Zoledronic acid was reviewed. The bone profile including calcium and phosphorus levels were monitored before and 4-24 hours after Zoledronic acid administration. The annual total Zoledronic acid dose was 0.1 mg/kg/year. Results: Post therapy, 46% of the treated children had mild hypocalcemia and 15% had mild hypophosphatemia. None of the children had hypocalcemic or hypophosphatemic signs or symptoms. No reports of seizure or tetany or muscle spasm. Conclusion: Hypocalcemia associated with Zoledronic acid administration is common, however mild. Close monitoring and calcium supplementation might be needed.