Effect of single high dose infusions of aminohydroxypropylidene diphosphonate on hypercalcaemia caused by cancer

Single intravenous infusions of 30 mg aminohydroxypropylidene diphosphonate were given to 16 patients who had malignant hypercalcaemia to assess host tolerance and the effect on serum calcium concentration. Ten of these patients also received intravenous rehydration or corticosteroids, or both. The serum calcium concentrations decreased significantly after treatment with aminohydroxypropylidene diphosphonate. Ten patients became normocalcaemic (normal range, adjusted for serum albumin, 2.25-2.75 mmol/l), two became hypocalcaemic, three showed decreases in serum calcium concentrations of more than 0.75 mmol/l, and one showed a decrease of more than 0.55 mmol/l. Only one patient had a minimum concentration greater than 2.77 mmol/l. Aminohydroxypropylidene diphosphonate was effective in metastatic and non-metastatic hypercalcaemia, and its hypocalcaemic effect was prolonged in some cases. There were no appreciable side effects. Single high dose infusions of aminohydroxypropylidene diphosphonate could replace conventional daily lower dose infusions, but the optimum frequency of high dose infusions remains to be determined.