[Diphosphonates in the treatment of hypercalcemia]

The diphosphonates (DP) represent a new class of therapeutic agents, the main property of which is to block bone resorption, irrespective of its stimulus. Apart from their remarkable results in Paget's disease of the bone, DP are very effective in the treatment of hypercalcaemia the osseus origin of which is nearly always essential. In malignant hypercalcaemia, EHDP, C12 MDP and APD, the three DP tested in man, cause a fall in serum calcium in a few days when administered intravenously. The latter two preparations are also effective when given orally. DP are also valuable in controlling hypercalcaemia in primary hyperparathyroidism. Research is under way to determine the role of DP in the prevention of malignant osteolysis, as distinct from the effects of chemotherapy.