[Treatment of neoplastic hypercalcemia using single-infusion diphosphonate]

40 patients with malignant hypercalcemia were treated with a single dose of APD, a potent inhibitor of osteoclast-mediated bone resorption. In order to establish a dose response in man, the patients were divided into four groups receiving 30, 45, 60 or 90 mg respectively as 24-hour infusion. Initial plasma calcium was similar in all groups except that receiving 90 mg, some of whose patients had higher initial values. All patients responded to APD with a rapid decrease of plasma calcium concentration from 3.44 +/- 0.10 mmol/l at day 0 to 2.33 +/- 0.06 at day 6, p less than 0.001). Plasma calcium became normal within 4 to 6 days in all patients but 6, all from the group receiving the low doses of APD (30 or 45 mg). Slight and asymptomatic hypocalcemia occurred in only 2 patients of the low dose groups, but in 6 of the high dose groups. A follow-up study in 40 patients showed that hypercalcemia recurred within 2 months in 6 patients of group 30 mg, in 5 patients of group 45 mg, in 1 patient of group 60 mg and in 2 patients of group 90 mg, whereas mortality was almost identical in the 4 groups. When retreated with a single dose of APD, all patients again showed normalization of calcemia. In all groups plasma phosphate, plasma creatinine and urinary calcium excretion decreased significantly. Clinical improvement was observed in all patients, with minimal side effects.(ABSTRACT TRUNCATED AT 250 WORDS)