Severe hypernatremia following treatment of the syndrome of inappropriate antidiuretic hormone secretion.

Treatment strategies for hyponatremia such as hypertonic saline, normal saline with furosemide, urea, fluid restriction and demeclocycline are well established. However, these treatment modalities may themselves be associated with life-threatening complications. An important complication is rapid correction of hyponatremia with its consequent serious neurologic deficits and death. An unrecognized complication is the development of severe hypernatremia as a result of strict fluid restriction and concomitant excessive free water excretion from prolonged outpatient demeclocycline therapy. The authors report a case of a patient with hyponatremia due to the syndrome of inappropriate antidiuretic hormone secretion who developed severe hypernatremia as a result of rigid fluid restriction and demeclocycline therapy.