[Effective demeclocycline therapy in a patient with over-secretion of antidiuretic hormone following head trauma].

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a common cause of hyponatremia. In this study a case of SIADH caused by head trauma is reported, in which severe hyponatraemia, escorted by life-threatening neurological symptoms was observed that could only be managed by parenteral sodium chloride infusions. Severe hyponatraemia was accompanied by elevated urinary sodium excretion, a characteristic sign of SIADH. After introducing the therapy with demeclocycline, a tetracycline type antibiotic that inhibits the renal action of antidiuretic hormone, serum sodium levels began to rise gradually, and the urinary sodium excretion slowly decreased. These observations show the effectiveness of demeclocycline in the treatment of SIADH.