Intermittent cyclical etidronate in the prevention of corticosteroid-induced bone loss

We conducted a prospective study of etidronate's effects on corticosteroid-induced bone loss in postmenopausal women with temporal arteritis for whom high-dose prednisone therapy was indicated. Group A (n = 10) received etidronate (400 mg/day for 2 weeks, then 11 weeks off etidronate; four cycles total) and prednisone: Group B (n = 10) received only prednisone. Vertebral bone mineral density (BMD) was measured blinded by dual X-ray absorptiometry. At 3, 6 and 12 months, vertebral BMD was significantly (P < 0.01) increased in Group A and decreased in Group B, based on mean actual and percent changes in BMD and mean changes in BMD Z-score from baseline. Between-group comparisons were also significant (P < 0.002) at each time point. No adverse events related to etidronate treatment were reported. Our results suggest that corticosteroid-induced bone loss may be prevented by instituting intermittent cyclical etidronate therapy when high-dose prednisone therapy is begun. Further research into bisphosphonate use in corticosteroid-induced bone loss (with larger patient populations, longer follow-up and fracture assessment) is warranted.