[Magnesium: therapeutic usefulness in emergency situations].

Magnesium has been a forgotten cation from the therapeutical point of view, given that, although its properties began to be known more than a century ago, its use has been always empirical or isolated. With respect to its use in emergency situations, in addition to correcting its deficit and using it for the treatment of hypercalcemia and hypopotassemia, it is currently recommended as the therapy of choice for the treatment and prevention of several arrhythmias. It can also be used to prevent its deficit, when such deficit is pathological or associated to the ingestion or certain drugs. Given the multiple properties of magnesium, controlled studies are required in order to define its potential therapeutical applications.