[Severe and acute hyponatremia in a schizophrenic patient with potomania]

Acute and severe hyponatremia causes a metabolic encephalothy. It is physiopathologically based on the cerebral edema, and its fatal symptoms include seizures and coma. We present a case of an extreme hyponatremia of multifactorial etiology in a schizophrenic patient with potomania. Potomania does not usually cause hyponatremia, unless it coexists with other trigger factors. This patient had a syndrome of inappropriate antidiuretic hormone (SIADH), and a deep hypokaliemia, due to vomiting and a treatment with indapamida, which perpetuates the deficit of extracellular sodium. In the patient's treatment, aripiprazole was the only recently introduced drug with which cases of inappropriate vasopressin secretion have been reported. Management of a severe hyponatremia must be considered a vital emergency, independent of the cause, and 3% hypertonic saline must be administered. The increase of the sodium level must not be higher than 25 mmol/L in the first 24-48 hours, to avoid a secondary brain injury.