Long-term therapy of Paget's disease of bone with EHDP.

Forty patients with Paget's disease of bone were treated with intermittent courses of the diphosphonate, EHDP. Seven individuals had prolonged remissions after their initial course of therapy, nineteen responded to retreatment with 5 mg/kg of EHDP for 6 months of each year, while 14 patients required cycles of 20 mg/kg for 1 month of every 4. Improvement was indicated by alleviation of symptoms and reduction in serum alkaline phosphatase and urinary hydroxyproline. Data suggesting a possible role for parathyroid hormone in the expression of Paget's disease are also discussed.