SUN-386 Treatment Outcomes of Intravenous Zoledronic Acid vs Oral Alendronate in Postmenopausal Women with Osteoporosis

In real practice, many patients with osteoporosis are poorly compliant with oral bisphosphonate, partly due to gastrointestinal side effects and partly due to medication procedure leading to premature termination of treatment. Once yearly intravenous zoledronic acid is well tolerated; little or no gastrointestinal effects and effective drug in treatment of postmenopausal osteoporosis with favourable dosing regimen to improve compliance of patients. So this study aims to study treatment outcomes of intravenous zoledronic acid vs oral alendronate in postmenopausal women with osteoporosis. This study was a randomized open label comparative study and included 94 postmenopausal women with osteoporosis. In this study, once yearly zoledronic acid (ZOL) infusion provided a greater reduction of serum procollagen type 1 N propeptide (P1NP) at 3 months than once weekly oral alendronate (ALN). Percentages of P1NP change in ZOL group was -70.25±17.51% and ALN group was -60.61±18.87% (P= 0.012). A decrease of P1NP ≥40% was observed in the majority of patients in both groups (89.4% in ZOL group and 85.1% in ALN group) (P= 0.536). ZOL was non-inferior to ALN in terms of BMD change at lumbar spine (4.8±5.5% in ZOL versus 4.9±4.5% in ALN treated patients) with P value of 0.922 and also at total hip (3.8±8.0% in ZOL versus 3.8±7.5% in ALN group) (P= 0.970). Two cases (4.3%) of new fractures was observed in ZOL group whereas 4 cases (8.5%) of new fractures occurred in ALN group over one year of study. The overall frequencies of treatment related adverse effects were similar between ZOL group (57.4%) and ALN group (42.6%) (P= 0.149). ZOL group showed significantly increased frequencies of musculoskeletal pain (57.4%) and acute phase reaction (12.8%) and 12.8% of participants in ALN group complained of heartburn. The overall preference to continue current medication was higher in ZOL group than ALN group (P= 0.002). The participants treated with ZOL were tend to have more satisfaction (P= 0.026) and willing to receive it longer period (P< 0.001).Compared to weekly oral alendronate therapy in treatment of postmenopausal osteoporosis, yearly infusion of 5 mg zoledronic acid infusion produced a significant greater response in serum P1NP at 3 months and similar change in BMD at one year of treatment and overall frequencies of adverse effects were similar between two treatment groups with excellent patient preference and satisfaction after zoledronate treatment. Reference: (1) Al-Bogami et al (2015) Favorable therapeutic response of osteoporotic patients to treatment with intravenous zoledronate compared with oral alendronate. Saudi Med J. 36(11):1305-1311. (2) Saag et al (2007) A single zoledronic acid infusion reduces bone resorption markers more rapidly than weekly oral alendronate in postmenopausal women with low bone mineral density. Bone. 40:1238-1243.