Effectiveness and Safety of Zoledronic Acid in the Treatment of Osteoporosis.

The effectiveness of current treatments for osteoporosis is limited by poor patient compliance. However, a favorable dosing regimen of zoledronic acid (ZA) has the potential to improve patient compliance and thus clinical outcomes. The author conducted a retrospective analysis to examine adherence to and the antiosteoporotic effects of a once-yearly infusion of 5 mg of ZA in Taiwanese patients with osteoporosis for up to 48 months. Five men and 149 postmenopausal women (mean age, 77.1 years) were included. Prior to ZA treatment, 66.2% of patients had fractures; most patients discontinued previous treatments due to compliance or convenience issues. Approximately 85% of patients received at least 2 infusions of ZA. Following ZA treatment, bone mineral density improved from baseline at 12 months (11% from baseline; P=.01) and 48 months (20.7% from baseline; P=.009). In addition there was a significant reduction in mean beta-C-telopeptide at all time points from 12 (P<.001) to 36 months (P=.010). New clinical fractures occurred in 16 (10.4%) patients, of which 12 patients experienced a single fracture. Zoledronic acid had an acceptable safety profile; no adverse events were considered to be drug related. Treatment with ZA improved bone health by enhancing bone mineral density and reducing bone turnover, even in high-risk patients. Low fracture rates and high adherence further elucidate the benefits of ZA in the treatment of osteoporosis.