Abstract
Cardiovascular disease is the leading cause of death in developed countries worldwide. In acute decompensated heart failure, hyponatraemia is common, often correlating with the severity of heart failure. In hyponatraemia, there is an excess of body water, for which therapy involves reducing water intake and increasing renal (electrolyte-free) water excretion. To achieve the latter, a new pharmacotherapeutic group has been introduced; the aquatic vasopressin antagonists, known as ‘vaptans’ (such as tolvaptan, satavaptan, etc.), which block vasopressin-2 (V2) receptors in the renal tubules. They have a unique mechanism of action; they promote water excretion and without affecting the excretion of other electrolytes (e.g., sodium ions). Vaptans have been shown to be effective in reversing hyponatraemia, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and in managing heart and liver failure. In this review, we describe the history, preparation, physicochemical properties, structure-activity relationships, and pharmacological properties, as well as mechanism of action of vasopressin antagonists.