Intravenous aminopropylidene bisphosphonate (APD) in the treatment of paget's bone disease

Abstract

We studied the effect of the intravenous administration of the bisphosphonate APD in 9 patients with Paget's bone disease. The medication was given in a daily dose of 25 mg for 7 days in 0.9% saline infusion over 2 hours. At the end of treatment a significant fall of serum calcium and phosphate was observed. The urinary excretion of calcium decreased markedly and the serum levels of the mid-molecule PTH fragment increased from (mean ± SE) 85 ± 11 to 122 ± 16 pg/ml (p < 0.05). A marked and rapid decline in the hydroxyprolinuria was observed from 297 ± 61 mg/24 h to 194 ± 51 mg/24 h (p < 0.01); meanwhile the serum alkaline phosphatase decreased from 102 ± 22 to 84 ± 21 KAU (p < 0.05). The effect of ADP on suppression of hydroxyprolinuria varied markedly from +1 to -81% and was negatively related to the basal hydroxyprolinuria (r = -0.90; p < 0.001). The duration of the bone turnover suppression was short. A relapse greater than 30% in hydroxyprolinuria was observed in 6 of 8 patients 2 to 3 months after APD withdrawal. The short-term intravenous administration of ADP is a useful means to rapidly suppress the activity of Paget's bone disease. However, further studies should determine the optimum dose, the length of treatment, and the need to associate oral therapy to induce a prolonged remission.