Zoledronic acid and risedronate in the prevention and treatment of glucocorticoid-induced osteoporosis (HORIZON): a multicentre, double-blind, double-dummy, randomised controlled trial

Introduction
Glucocorticoid drugs are a mainstay of treatment in many inflammatory and immune-mediated disorders.1 However, persistent use is associated with side-effects, such as bone loss and increased fracture risk.2, 3, 4, 5 and 6 This increased risk is apparent in some patients within 3 months of starting glucocorticoids.4 and 7

Prevention and treatment of glucocorticoid-induced osteoporosis is best established for bisphosphonates,5 a class of drugs that increase bone mineral density and reduce vertebral fracture risk in patients beginning or continuing glucocorticoid treatment.8, 9 and 10 Daily oral bisphosphonate therapy has been approved for the treatment and prevention of g