Safety and effectiveness of once-yearly zoledronic acid in Japanese osteoporosis patients: three-year post-marketing surveillance

The safety analysis and effectiveness analysis sets included 1406 and 1387 patients, respectively, with mean age of 76.5 years. Adverse reactions (ARs) occurred in 19.35% of patients, with an acute-phase reaction in 10.31, 1.01, and 0.55% after the first, second, and third ZOL infusions. Renal function-related ARs, hypocalcaemia, jaw osteonecrosis, and atypical femoral fracture occurred in 1.71, 0.43, 0.43, and 0.07% of patients, respectively. Three-year cumulative fracture incidences were 4.44% for vertebral, 5.64% for non-vertebral, and 9.56% for clinical fractures. BMD increased by 6.79, 3.14, and 1.78% at the lumbar spine, femoral neck, and total hip, respectively, after 3-year treatment. Bone turnover markers remained within reference ranges. Treatment persistence was 70.34% over 2 years and 51.71% over 3 years. Male, age ≥ 75 years, no previous medicines for osteoporosis, no concomitant medicines for osteoporosis, and inpatient at the first infusion were related to discontinuation. There was no significant difference in the persistence rate between before and after the COVID-19 pandemic (74.7% vs. 69.9%; p = 0.141).