Management of disorders of calcium homoeostasis.

Severe hypercalcaemia may be life-threatening and requires prompt management. Whatever the cause, the aim of therapy should obviously be to eradicate the source of hypercalcaemic factors. After rehydration, which is an essential first step in the management strategy, and after evaluation of the prevailing pathogenetic mechanism, the acute treatment will be aimed at increasing urinary Ca excretion and inhibiting bone resorption. Among the various pharmacological agents, bisphosphonates appear to be the drugs of first choice, because of their efficacy and their virtual absence of side-effects. The decision to treat hypocalcaemia is determined by the extent of the symptoms and the risk of complications. The treatment of acute hypocalcaemia comprises the parenteral administration of Ca or magnesium, when magnesium deficiency can be suspected. Then, chronic hypocalcaemia may require the use of 1,25-dihydroxyvitamin D, once the replenishments of vitamin D stores have been assured.