Suspect when there is water retention (antidiuresis) associated with an empty bladder and dilutional hyponatremia. There is no hypertension or edema.
Once suspected low serum sodium and osmolality accompanied by a high urine osmolality.
Demethylchlortetracycline (demeclocycline) in patients unresponsive to fluid restriction. It may cause photosensitivity.
Severe hyponatremia is treated by hypertonic saline combined with frusemide to avoid volume overload.