[The long-term results of ethanehydroxydiphosphonate treatment in Paget's disease of bone]

Long-term results after ethanohydroxy diphosphonate treatment (EHDP) using a dose of 5/7.5 mg/kg/day over a 2 to 18 months period (x = 6.8) in a group of 45 cases of Paget disease, out of which 24 (53%) are male, are presented. An exam was programmed before and after treatment (12, 24 and 60 months). A clinical remission occurred in 75% of patients which lasted for at least 5 years in 51% of them. The average reduction of alkaline phosphatase levels was approximately 50% of baseline values (p less than 0.001) maintained with small variations up to the end of the study. There was no relapse in the last control performed in 49% of cases and 9 of them are from a 5 year follow up. On the contrary 11 patients (24%) did not show biochemical relapse however none of the characteristics analyzed permit the prediction of the type of response. The doses do not significantly influence the intensity either. We have observed scarce radiologic modifications although two patients showed a discrete improvement in the first revision and a worsening at different stages of their evolution was evidenced in two more cases. Altogether, these results confirm the long-term efficacy of treatment with EHDP at low doses at which it presents few adverse effects. The possibility of an structural deterioration advises to avoid its use in those cases with lytic lesions in load-bearing bones.