Abstract

Abstract Background: Oral bisphosphonates have been demonstrated to be effective in treating osteoporosis. However, there has been a significant problem with compliance. Newer intravenous bisphosphonates are available for osteoporosis management, but have not been compared with oral bisphosphonates in a clinical setting. Aims: To compare the safety and effectiveness of intravenous zoledronic acid (ZOL) and oral alendronate (ALN) in osteoporotic patients following a low trauma fracture . Method: A non-randomised, retrospective cohort study was conducted of 169 patients with a low trauma fracture and reduced bone mineral density (BMD). Patients were treated with either an infusion of 4mg ZOL or ALN 70mg weekly. The outcomes measured were change in BMD after 12 months of treatment with either bisphosphonate, and new osteoporotic fractures. All adverse events were documented. Results: Lumbar spine BMD (L2-L4) improved 5.6% in the ZOL group (p < 0.001) and 5.5% in the ALN group (p < 0.001). Total hip BMD improved 2% in the ZOL group (p < 0.01) and 2.5% in the ALN group (p < 0.001). There was no significant difference in BMD change between the groups. There were significantly more new fractures (p < 0.001) in the ZOL group (7.2%) than the ALN group (1%). The ZOL group were significantly older (p < 0.01) and had a significantly higher proportion of males (p < 0.05) at baseline. There were no serious adverse reactions in either group. Conclusions: ZOL and ALN both produce a significant increase in BMD and are well tolerated in patients with osteoporotic, low trauma fractures. Yearly ZOL provides a safe, convenient alternative to weekly oral bisphosphonates.