Efficacy of aminohydroxypropylidene diphosphonate in the treatment of malignancy-associated hypercalcaemia

Two patients with symptomatic malignancy-associated hypercalcaemia were treated with intravenously-administered aminohydroxypropylidene diphosphonate (APD). Both patients demonstrated dramatic falls in serum calcium concentration, and in urinary calcium and hydroxyproline excretion that were consistent with a reduction in the rate of bone resorption. Normocalcaemia occurred by day 5 and persisted for approximately three weeks after treatment. No significant side-effects were encountered. It was concluded that APD is a promising new agent in the management of hypercalcaemia that is associated with malignant disease and warrants further investigation.