Efficacy of antiresorptive agents for preventing fractures in Japanese patients with an increased fracture risk: review of the literature.

The aim of the present review was to clarify the efficacy of currently available potent antiresorptive agents for preventing fractures in Japanese patients with an increased fracture risk. PubMed was used to search the literature for randomized controlled trials (RCTs), with the following search terms: fracture, etidronate, alendronate, risedronate, minodronate, raloxifene, bazedoxifene and Japan. The inclusion criteria were papers written in English, ≥50 subjects per group and a study period of ≥1 year. Fourteen RCTs met these criteria. The efficacy of antiresorptive agents for preventing vertebral, nonvertebral and hip fractures was investigated. There was evidence that raloxifene reduced the incidence of clinical vertebral fractures, while etidronate, alendronate and minodronate (but not bazedoxifene) reduced the incidence of morphometric vertebral fractures in patients with postmenopausal or involutional osteoporosis. Head-to-head trials showed that alendronate and raloxifene had similar efficacy for preventing vertebral fractures in patients with postmenopausal osteoporosis, while risedronate was not inferior to etidronate for reducing the incidence of morphometric vertebral fractures in patients with involutional osteoporosis. Alendronate reduced the incidence of hip fractures in patients with Parkinson's disease, and risedronate reduced the incidence of nonvertebral fractures and hip fractures in patients with Alzheimer's disease or stroke. In conclusion, the present review confirmed the efficacy of etidronate, minodronate and raloxifene for the prevention of vertebral fractures, the efficacy of alendronate for vertebral and hip fractures, and the efficacy of risedronate for vertebral, nonvertebral and hip fractures in Japanese patients with an increased fracture risk.