[Treatment of Paget's disease of bone with ethane-1 hydroxy-1, 1 diphosphonate at low dosage (author's transl)].

Fifty-one patients with Paget's disease were treated during 6 months with ethane-01 hydroxy-1, 1 diphosphonate (EHDP, etidronate) in doses of 5 mg/kg/day. The drug was most effective in relieving pain, at the same time diminishing the uptake of pagetic lesions on quantitative bone scans and lowering by almost 70% the abnormally high serum alkaline phosphatase levels and 24-hour hydroxyproline urinary levels. Histologically, the resorption surfaces and the number of osteoclasts per mm2 of bone tissue were significantly reduced. On follow-up, the improvement persisted for at least one year after treatment was discontinued. EHDP was well tolerated clinically and biologically, and on histological sections no accumulation of osteoid tissue due to impaired mineralization was seen. EHDP at the 5 mg/kg/day dose appears to be effective in the treatment of Paget's disease.