Osteoporosis may predispose to vertebral compression fractures which occur in 30–50% of patients on prolonged glucocorticoids. Steroid-induced bone loss may be reversed with cyclical administration of etidronate ¹⁾ in 4 cycles of 400 mg/d ✖ 14 days followed by 76 days of oral calcium supplements of 500 mg/d (not proven to a reduced rate of vertebral fractures).