281 Side-effects associated with IV Zoledronic Acid infusion in patients with osteoporosis

Abstract Background Osteoporosis is a common condition affecting bone, leading to fragility and fractures. Oral bisphosphonates are the first line treatment for osteoporosis reducing vertebral, hip and non-vertebral fractures. However poor compliance and Gastro-Intestinal (GI) intolerance result in poor persistence. Intravenous Zoledronic Acid (IV ZA) is an effective alternative therapy, improving compliance and tolerability. Side effects have been reported such as fever, flu-like symptoms, myalgia, arthralgia, headache, uveitis, iritis and hypocalcaemia. Methods This prospective observational study was carried out in a dedicated Bone Health Service. Patients diagnosed with osteoporosis were assessed by the Bone Health team regarding suitability for IV ZA. Infusions were administered in a nurse-led IV ZA clinic. Pre and 1-week post infusion bloods including Renal, Liver and Bone profile, Parathyroid hormone, Vitamin D and bone markers- Osteocalcin, CTX, PINP were taken. Side effects post infusion were recorded. Results N = 189. 161:28 female to male ratio. Age range 32-90 years, median 61 years. All diagnosed with osteoporosis in hip and/or spine. Forty-three percent were bisphosphonate naïve. 51 (27%) attended GP for post infusion bloods while 7 patients received infusion while inpatients. 29% of those returning to clinic for post infusion bloods reported side effects. Treatment naïve and treatment experienced reported similar rate of side effect 21%/20% respectively. Most common side effects include flu-like symptoms (31%) with fatigue/tiredness/generalised aches and pains/GI upset 16% respectively. 10% reported headaches while 5% experienced sore/swollen eyes. Rash, swollen joints and pre-syncope experienced by 3% respectively. Symptoms resolved after 24-48 hrs. Conclusion IV ZA is a well-established treatment for osteoporosis particularly for patients intolerant or poorly compliant with oral bisphosphonate therapy and an accepted treatment to close-off Denosumab. According to our study IV ZA is well tolerated with self-limiting side effects. However, pre infusion screening is essential to deem suitability.