Nasal desmopressin (DDAVP) is a commonly prescribed antidiuretic hormone (ADH) analogue used for treatment of diabetes insipidus, polyuria and nocturnal enuresis. Although it is generally well tolerated, it can cause severe electrolyte imbalance. Numerous reports exist on cases of mild to moderate DDAVP-induced hyponatremia, yet few reports describe severe hyponatremia (Na