Determinants of remission of Paget's disease of bone.

Bisphosphonates are a safe and effective treatment for Paget's disease of bone, but little information is available about the factors influencing the duration of remission so obtained. We assessed 60 patients with Paget's disease treated with disodium pamidronate (APD). The mean duration of remission was 9.5 months (range 3-25). The major influences were the initial pretreatment alkaline phosphatase (ALP; r = -4.6, p < 0.0001), minimum posttreatment ALP (r = -0.51, p < 0.0001), and the rate of response of bone turnover to the first dose of APD (r = 0.61, p < 0.0001). Multiple linear regression showed that the initial response to treatment was the most significant influence. Also, despite a minimum ALP within the normal range, the duration of remission varied considerably (4-25 months). This may be due to the difficulties in applying a population-based normal range to individuals.