Safety and effectiveness of zoledronic acid therapy used in osteogenesis imperfecta patients

Abstract

Introduction: Osteogenesis imperfecta is an inheritable disease characterized by deficiency of collagen type 1 due to mutation in CO1A1 and CO1A2 genes which leads to an increase in bone fragility and fractures rate. Most medical centres use pamidronate for standard treatment of osteogenesis imperfecta. However, zoledronic acid is used for the standard treatment of osteoporosis, and it has higher potency than pamidronate and faster intravenous infusion. Few studies have demonstrated the safety and effectiveness of zoledronic acid in patients with osteogenesis imperfecta. Objectives: The aim of our retrospective chart review study was to estimate the safety and effectiveness of zoledronic acid in patients with osteogenesis imperfecta. Methods: The study included 16 patients diagnosed with osteogenesis imperfecta at King Abdulaziz Medical City, Jeddah, within the last 10 years (10 males and 6 females) with a mean age of 8.9±5.2, all patients received zoledronic acid therapy and they were monitored before and after treatment. Results: It was found that the average number of fractures in patients before using zoledronic acid was 3.8±1.8, which dropped after zoledronic acid dropped to 0.93±1.2. The difference in fractures was significant, with a mean of 2.8±1.2 (P≤ 0.05). After zoledronic acid therapy the mean functional measures were as follows: calcium level 2.4mmol/l, phosphate level 1.5mmol/l, alkaline phosphatase level 223IU/l and vitamin D level 50nmol/l. Conclusion: The study showed that using zoledronic acid therapy in osteogenesis imperfecta patients was effective as it significantly decreased the number of fractures. Since calcium and vitamin D profiles were within normal range this indicates zoledronic acid therapy is safe. Infusion of zoledronic acid is convenient for the patient since it requires a one-day admission as opposed to a three-day admission for pamidronate infusion. Further studies are required to standardize the optimal dosing and improve the efficacy of the treatment.