Clinical suspicion
Suspect when there is water retention (antidiuresis) associated with an empty bladder and dilutional hyponatremia. There is no hypertension or edema.
Diagnosis
Once suspected low serum sodium and osmolality accompanied by a high urine osmolality.
Treatment
Fluid restriction.
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.
