VPA-985 IN PATIENTS WITH HYPONATREMIA

抗利尿激素（AVP）是一种多肽激素

Vasopressin (AVP) is a peptide hormone actively involved in the regulatin of body fluid osmolality, blood volume, blood pressure, and cell prliferation via the stimulation of specific membrane-bound receptors classified into pituitary subtypes having distinct pharmacological profiles and intracellular second messengers. The secretion of AVP is an absolute requirement for the maintenacne of fluid homeostasis. An agent that increases urine output by producing a free water diuresis would be a significant advantage in conditions such as hyponatremia of congestive heart failure, liver chirrhosis, nephrotic syndrome and the syndrome of inappropriate secretin of antidiuretic hormone (SIADH). This study is designed to evaluate the effecacy, safety, and tolerance of VPA-985, a selective non-peptidic orally active AVP antagonist, in patients with hyponatremia due to drug induced SIADH. Preliminary pharmacokinetic and pharmacodynamic parameters will be asessed.