Effects of amino-butylidene diphosphonate in hypercalcemia due to malignancy.

We studied the effect of a single 5 mg intravenous infusion of amino-butylidene diphosphonate (ABDP) in nine patients with hypercalcemia of malignancy, in whom serum calcium values were stable or rising after intravascular volume expansion. Serum calcium fell progressively in all patients and in seven reached the normal reference range by day 6 (p less than 0.001). The decrease in serum calcium was associated with a decrease in the fasting urinary calcium/creatinine ratio (p less than 0.05). Hypercalcemia recurred in seven of the patients by day 12, but two patients remained normocalcemic for 21 days. We conclude that ABDP is a highly potent diphosphonate and that a single intravenous infusion is capable of inhibiting tumour-mediated bone resorption for several days.