Effects of disodium dichloromethylene diphosphonate on Paget's disease of bone.

19 patients with Paget's disease were treated orally for 6 months with disodium dichloromethylene diphosphonate. 1600 mg/day (10 patients) significantly reduced urine hydroxyproline, serum alkaline phosphatase, urine calcium, and the number of pagetic bone osteoclasts. Tetracycline double labelling revealed undisturbed bone mineralisation. There was improvement on quantitative bone-scans and bone pain diminished. There was a transient increase in parathyroid hormone level in 13 of the 19 patients during treatment, which was associated with a high serum 1,25 (OH)2D3. No adverse clinical side-effects have been observed and biochemical remission has persisted for 9 months.