Effects of Dichloromethylene Diphosphonate on Skeletal Mobilization of Calcium in Multiple Myeloma

Abstract

Dichloromethylene diphosphonate (Cl₂MDP), an inhibitor of osteoclast activity, was evaluated for its ability to decrease the excessive mobilization of skeletal calcium that complicates multiple myeloma. Ten patients with active myeloma, widespread bone disease, and hypercalciuria were studied in a double-blind, placebo-controlled, crossover-designed trial in which they took Cl₂MDP for eight weeks and placebos for eight weeks. Two patients died during the placebo phase; of eight patients who received Cl₂MDP, seven had rapid, sustained, and highly significant (P2MDP and not from improvement in the underlying disease. We conclude that Cl₂MDP is a potentially useful inhibitor of osteoclast-mediated bone erosion in multiple myeloma. (N Engl J Med 302:310–315, 1980)