Efficacy and Safety of Annual Infusion of Zoledronic Acid and Weekly Oral Alendronate in the Treatment of Primary Osteoporosis: A Meta-Analysis

This systematic review and meta-analysis aimed to reveal the efficacy and safety of zoledronic acid compared with alendronate in patients with primary osteoporosis. The PubMed, Embase, and the Cochrane Library databases were searched from the establishment of each database to April 2022 for comparative studies on the topic, including randomized controlled trials (RCTs) and cohort studies, and 2 authors individually extracted information and data concerning study design, baseline characteristics, bone mineral density (BMD), bone turnover markers, and adverse events (AEs). We identified 8 eligible trials, including 1863 participants. Pooled estimates demonstrated that, compared with alendronate, zoledronic acid showed no significant difference in increasing the BMD of the lumbar spine after 1 year (SMD = -0.03, 95%CI -0.15 to 0.09, I-2 = 0.41%) or after 2 years (SMD = 0.16, 95%CI -0.12 to 0.43, I-2 = 63%), and the BMD of the total hip after 1 year (SMD = -0.08, 95%CI -0.31 to 0.14, I-2 = 64%) or after 2 years (SMD = 0.05, 95%CI -0.21 to 0.32, I-2 = 61%). No significant difference in improving bone turnover markers, including serum C-terminal cross-linking telopeptide of type-1 collagen, urine N-terminal cross-linking telopeptide of type-1 collagen, and serum procollagen type-1 N-terminal propeptide, were found, whereas significantly higher total AE rates (RR = 2.27, 95%CI 1.60 to 3.21, I-2 = 75%) were recorded within 3 days of infusion, but some lower AE rates, particularly of gastrointestinal AEs (RR = 0.6, 95%CI 0.44 to 0.83, I-2 = 37%), were noted after 3 days of infusion. Compared with alendronate, zoledronic acid has achieved comparable therapeutic results in the treatment of primary osteoporosis in increasing BMD and reducing bone turnover marker levels. Zoledronic acid showed a better safety profile than alendronate with long-term use, especially with regards to gastrointestinal-related AEs.