SIADH, as its name suggests, is an inappropriate secretion of antidiuretic hormone (ADH). ADH is a hormone that helps control your sodium concentration and your blood pressure by adjusting the ...
Tolvaptan is a vasopressin receptor antagonist. Vasopressin (a.k.a. ADH or antidiuretic hormone) helps to regulate water retention by absorbing water in the collecting ducts of the nephron.