Persistent effect of zoledronic acid in Paget's disease

Paget's bone disease is a disorder in which bone regions with high turnover are replaced by new, vascular, but disorganized and immature bone with excessive fibrosis, high tendency of deformity and diminished mechanical resistance. Treatment aims at the suppression of osteoclast activity and is achieved with bisphosphonates, which represent the treatment of choice for Paget's disease. Zoledronic acid, a relatively new member of this class, normalizes alkaline phosphatase in the majority of patients and has a favorable safety profile. We report the case of an asymptomatic patient who was diagnosed with Paget's disease based on typical biochemical, radiological and histological findings and was treated with a single intravenous infusion of 4 mg of zoledronic acid. No side effects were observed. Alkaline phosphatase levels normalized within four months. At the last follow up examination, three years after treatment, the patient remains asymptomatic, without significant changes in radiology imaging, and alkaline phosphatase levels are still within the normal range. In conclusion, zoledronic acid, apart from being safe and effective in Paget's disease, also appears to be able to achieve significantly prolonged remissions.