Hyponatremia in the syndrome of inappropriate secretion of antidiuretic hormone: rapid correction with osmotic agents.

In three patients with SIADH, mannitol or glycerol promoted a rapid free water diuresis. Use of osmotic agents requires less laboratory and clinical monitoring than use of furosemide, is appropriate treatment, and in fact may be the treatment of choice in some patients with symptomatic hyponatremia from SIADH.