Short-term treatment of Paget's disease of bone with ipriflavone

Ipriflavone (IP), an isoflavone derivative, seems to prevent the loss of bone mass through the inhibition of bone resorption, mainly inhibiting the recruitment of osteoclasts. We investigated whether a brief course of treatment with IP can reduce biochemical parameters of accelerated bone turnover and bone pain in patients with active Paget's disease of bone. Sixteen patients (9 males and 7 females) with active Paget's disease were randomly allocated to two different crossed-over dose regimens of treatment with IP (600 mg/day vs. 1200 mg/day). Each treatment course lasted 30 days and the wash-out period between the two sequences was 15 days. Serum alkaline phosphatase (Al.Ph.) and urinary hydroxyproline/creatinine excretion (HOP/Cr) were reduced after each sequence. At the end of the 600/1200 mg/day treatment sequence, serum Al.Ph. and HOP/Cr decreased with 32% and 25.6% respectively. At the end of the 1200/600 mg/day treatment sequence, serum Al.Ph. and HOP/Cr decreased with 33% (P < 0.01) and 24.1% (P < 0.05) respectively. Furthermore, a significant decrease in bone pain was observed during the 1200/600 mg/day sequence (P < 0.01). Both treatment schedules were well tolerated and the patients' compliance resulted excellent. Our results indicate that short-term treatment with IP can reduce biochemical parameters of disease activity and bone pain in patients with active Paget's disease of bone.