Single-day intravenous pamidronate in Paget's disease

Although the efficacy of pamidronate (APD) in Paget's disease is established, the optimal dose and regimen are not known. In this article, further findings using a single-day intravenous infusion are reported, comparing the responses of 114 subjects treated with doses of 20 mg (n = 35), 30 mg (n = 26), 45 mg (n = 29), and 60 mg (n = 24). Assessments of clinical and biochemical response were made at 2, 4, 8, 12, and 24 weeks. Patients with persistent disease activity were retreated after 24 weeks. The single-day infusion of APD was followed by a rapid and sustained biochemical response, but in only 24% of patients did alkaline phosphatase (AP) levels normalize. Of patients in whom the serum AP level normalized, 93% had initial values less than three times the upper limit of normal. Although there was no significant difference in response between the lower dosage groups, there was a greater response in patients treated with a higher dose of APD. The percentage decrease in AP from baseline was similar after the first and second infusions. These findings show that a single-day infusion of APD is effective in the treatment of Paget's disease and that a dose-response relationship exists.