AB1016 Zoledronic acid: Five years experience results in patients with bone mineral pathology

Background It has been demonstrated that Zoledronic acid reduces the risk of fractures, both vertebral and non-vertebral, in postmenopausal osteoporosis. Results of the 6-year extension study HORIZON-PFT have recently been published1. No differences have been found between 3 vs 6 year treatment, regarding the BMD in femoral neck (primary endpoint) nor side effects (but lower incidence of arterial hypertension). However, taking into account results related to the reduction of vertebral fracture risk (secondary endpoint), authors suggest that patients at a higher risk for this type of fracture could benefit from 6 years of treatment. Objectives To describe the results after 5-year use of Zoledronic Acid in our department, in patients with bone mineral pathology. Methods Descriptive study, both retrospective and cross-sectional, including all patients treated with Zoledronic acid from 2006 till January 2012 in our department. Data collected included gender, age, diagnosis, number of infusions, new fractures, alkaline phosphatase (ALP) level before and after the first dose, and side effects. Results 212 patients were included: 175 (82.50%) diagnosed with osteoporosis (OP), 32 (15.10%) Paget’s Disease (PD) and 5 (2.40%) other. 171 patients (80.60%) were female and 41 (19.40%) were male. The average age of the sample was 68±10 year. 39.15% had just one Zoledronic acid dose, 35.85% had two doses, 18.87% had three and 6.13% had four. We detected 43 adverse events, happening in 19.34% of the patients: 63% consisted in a flu-like syndrome and 21% in arthralgia. Other less frequent (one each) side effects were jaw osteonecrosis, uveitis, interstitial nephritis, fever, pruritus, nausea, lower limb oedema, arthritis and hypertensive crisis. Treatment was stopped in 4 patients (1.88%) due to side effects. No atrial fibrillation or atypical fractures were detected. The average of new fractures after at least one dose was 5.18%. Among PD patients, 16 had high levels of ALP before treatment, normalizing in 11 cases (68.75%) after the first infusion. Conclusions As in previous publications, our results suggest that Zoledronic Acid has a good safety profile. Nevertheless, in some cases treatment was stopped due to side effects. The percentage of new fractures after infusion was lower (5.18%) in our patients than in the HORIZON-PFT study (8.4%). As a limitation of our study, it must be mentioned that data was collected from medical files without an established protocol. It wo