[Treatment of Paget's disease with low dose sodium etidronate (5mg/kg/day). Occurrence of reversible transient suspected leukopenia].

27 patients with Paget's disease, from 51 to 80 years of age, were treated with etidronate disodium at a dose of 5 mg/kg/day. 70 percent of patients had multiple bone involvement. Six patients had previously been treated with diphosphonates, and nine had previously received synthetic pork or salmon calcitonin. The following parameters were studied: the serum alkaline phosphatase, urinary hydroxyproline, a self-assessment scale to evaluate pain and a scale to assess improvement in functional capacity. From the first month of treatment, significant improvement in pain indices was noted and over the following two months there was an associated significant regression in parameters of bone resorption and formation. The clinical and laboratory improvement brought about with diphosphonates persisted three months after cessation of therapy in 88 percent of cases. Gastrointestinal tolerance of the drug was excellent, but three cases of transitory leukopenia occurred which resolved spontaneously, requiring in two cases cessation of therapy. Even though it is impossible to correlate with certainty this previously undescribed finding to therapy with etidronate disodium, we believe that at a dose of 5 mg/kg/day, the drug provides rapid, effective, long term treatment in Paget's disease, but that regular hematologic surveillance should be performed.