The Superiority of Zoledronic Acid Over Risedronate for Paget's Disease: A 16-Year Experience at a Single Institution.

Introduction Bisphosphonates are considered to be the treatment of choice for patients with active Paget's disease. The aim of this study was to record and assess the therapeutic effect in response to a single intravenous infusion of 5mg zoledronic acid or oral risedronate. Methods A retrospective observational study was conducted of 89 patients in Greek patients with active Paget's disease from a tertiary hospital in North Greece. Patients were treated with either a single intravenous infusion of 5mg zoledronic acid (1st group, n=46) or 30mg of risedronate per day for 60 days (2nd group, n=43). All patients received 1000mg of calcium and 400-800IU of calciferol daily. The primary outcome measure was to record the therapeutic response defined as the control of patients' symptoms and normalization of the biochemical markers of bone metabolism. The secondary outcome measures included the patient's quality of life which was evaluated by the questionnaire SF-36 and adverse events. Results Forty patients from the zoledronic acid group and 38 patients from the risedronate group, who reported pain at the beginning of the study, showed a significant degree of clinical improvement. All the patients in our study showed a therapeutic response at six months while the remission was persistent at 36 months. There was a statistically significant difference between pre-treatment basal results and values at the sixth and 36th months of treatment (p<0.001) between the two groups. Conclusion The study demonstrated the superiority of zoledronic acid over risedronate in patients with active Paget's disease.