A randomized, double-blind comparison of risedronate and etidronate in thetreatment of Paget's disease of bone

PURPOSE: To compare the efficacy and tolerability of oral risedronate and e tidronate for treatment of Paget's disease of bone. PATIENTS AND METHODS: Patients from 12 centers in North America received ri sedronate 30 mg daily for 2 months (62 patients) or etidronate 400 mg daily for 6 months (61 patients) in a prospective, randomized, double-blind stud y. Serum alkaline phosphatase (the primary variable), serum bone-specific a lkaline phosphatase, and urinary deoxypyridinoline concentrations were moni tored for 12 to 18 months. RESULTS: Serum alkaline phosphatase concentration normalized by month 12 in 73% of risedronate-treated patients, compared with 15% of those receiving etidronate (P < 0.001). Median time to normalization was 91 days for risedr onate-treated patients and >360 days for etidronate-treated patients (P < 0 .001); relapse rates were 3% in the risedronate group and 15% in the etidro nate group (P < 0.05). At month 18, 53% of the risedronate group and 14% of the etidronate group remained in biochemical remission. Urinary deoxypyrid inoline normalized in 87% of patients on risedronate and 57% of patients re ceiving etidronate (P < 0.01); serum bone-specific alkaline phosphatase nor malized in 73% of patients on risedronate and 18% of patients on etidronate (P <0.001). Patients who had received etidronate previously had a blunted response to etidronate, but not to risedronate. Reductions in pain were sta tistically significant in the risedronate group, but not in the etidronate group. Both drugs were well tolerated. CONCLUSION: Although etidronate is effective, risedronate offers a shorter duration of therapy, better and longer-lasting remission, significant reduc tions in pain, and provides additional remission in subjects who exhibited an incomplete response to previous etidronate treatment. (C) 1999 by Excerp ta Medica, Inc.