syndrome of inappropriate secretion of antidiureti

= SIADH

a condition of inappropriately high plasma levels of ADH (see vasopressin) with associated water retention, dilutional hyponatraemia, and the production of highly concentrated urine. Renal, adrenal, thyroid, and hepatic function are normal, as is the volume of circulating blood (euvolaemia). It is caused by a variety of pathological conditions, usually intrathoracic and intracerebral, and also by a number of drugs, including antidepressants, chemotherapy agents, and some of the older antidiabetic agents. The treatment involves fluid restriction, treatment (or removal) of the underlying cause (or drug), and, in severe cases, administration of demeclocycline to reduce the effects of ADH on the kidney. Very rarely, hypertonic saline is given.