RT Journal Article SR Electronic T1 AB0821 Evolution of The Values of Alkaline Phosphatase (ALP) in Patients Treated with Zoledronic Acid and Diagnosed with The Paget's Disease of Bone JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 1184 OP 1184 DO 10.1136/annrheumdis-2016-eular.5919 VO 75 IS Suppl 2 A1 M. Retuerto A1 L. Sierra A1 M. Martín A1 C. Moriano A1 A. García A1 M. Garijo A1 C. Iniguez A1 A. Lopez A1 C. Άlvarez A1 E. Díez A1 T. Pérez YR 2016 UL http://ard.bmj.com/content/75/Suppl_2/1184.2.abstract AB Background The indication or use of zoledronic acid on the Paget's disease of bone was approved in 2005. Recent studies point out the administration of a single intravenous dose of this medicine as the first therapeutic option.Objectives The aim of this study is to determine whether there is improvement in the ALP values among the patients with Paget's disease of bone after the administration of the zoledronic acid and to analyze whether this improvement is greater in the group previously treated with oral bisphosphonates or in the group who have not received prior treatment.Methods This is a retrospective study which included 49 patients with Paget's disease of bone that were examined by the rheumatology department and that have been registered in a retrospective database since 2010.The independent variables included were age, gender, smoking habits, presence of diabetes mellitus, date of first treatment, doses received, corticosteroid therapy, presence of concomitant inflammatory disease, complications after treatment, fractures after the administration of the drug and pretreatment with oral bisphosphonates.Results The mean age of patients was 75±9,84 years [53–97]. 25 patients (51%) were male and 24 (49%) were female. 29 patients (59.2%) non-smokers, 10 (20.4%) former smokers, and 10 (20.4%) current smokers. 9 patients (18.4%) were diabetic. 26 patients had not received prior treatment with oral bisphosphonates, while 23 had been previously treated. 2 patients were treated with corticosteroids. 7 patients had active cancer, one patient had rheumatoid arthritis and one patient had another type of inflammatory disease. One patient developed fever as a post-infusion complication; however, this side effect did not require the discontinuation of therapy. Two patients required reinfusion due to the resurgence of the Paget and due to the high levels of ALP after the first dose. The mean dose received was 1.12± 0.389. One patient had a fracture after the administration of the drug.There is a statistically significant difference between the average ALP prior to the initiation of treatment with zoledronic acid and after the treatment in both groups of patients. Nevertheless, when comparing both subgroups of patients (treated or not previously with bisphosphonates), there is a greater difference in the subgroup of patients who had not received prior treatment compared to those that had been treated with oral bisphosphonates.Conclusions * Zoledronic acid treatment is effective in reducing the ALP levels in patients with Paget's disease of bone.* The difference in ALP levels after the zoledronic acid administration with respect to the previous ones is higher in the group of patients not previously treated with oral bisphosphonates.Tucci JR. Zoledronic acid therapy of patients with paget disease of bone resistant to or with unsustained remission following prior bisphosphonate therapy. Endocr Pract. 2015 Oct;21(10):1111–6. doi: 10.4158/EP15664.OR.Baykan EK, Saygılı LF, Erdogan M, Cetinkalp S, Ozgen AG, Yilmaz C. Efficacy of zoledronic acid treatment in Paget disease of bone. Osteoporos Int. 2014 Sep;25(9):2221–3. doi: 10.1007/s00198-014-2752-z.Disclosure of Interest None declared