siadh
"My father had a head injury 3 weeks back, had mild sub-arachnoid hemorrhage, no surgical intervention was required, was being treated conservatively. But he developed persistent hyponatremia, his serum sodium level gradually went down to 104 mEq/L. After a battery of investigations, it was diagnosed as SIADH. Despite all efforts to correct his serum sodium level, it was seesawing between 104 and 108. Strident fluid restriction and aggressive hypertonic saline therapy even baffled. Then we started Tab Demeclocycline 300 mg thrice daily and it magically started causing its much desired adverse effect of producing more watery and less saline urine on its second day! Kudos to this wonderful gut-sterilizer! My father is getting improved."