[Dichloromethylene diphosphonate in the treatment of lytic bone metastases]

Dichloromethylene diphosphonate (Clodronate) has powerful activity against osteoclasts. We studied its effects on calcium balance in patients with malignant osteolytic lesions. Ten normocalcemic patients with advanced metastatic bone disease or myeloma were evaluated in a baseline 20-day calcium balance and kinetic study. They were then randomized to a clodronate or placebo regimen, treated intravenously for two weeks and orally for a month, and finally re-evaluated in another 20-day balance and kinetic study, conducted while they were still receiving treatment. The results show that both calcium balance and calcium absorption increased from base line in the clodronate group and that these changes were significantly different from those in the placebo group. There was a marginal decrease in bone resorption in the clodronate group and no change in bone accretion. Our results suggest that clodronate may be a useful adjuvant in managing metastatic bone disease.