By: Saparja Nag  Apr. 19, 2018

Samsca was developed by Otsuka Pharmaceutical to treat hyponatremia as a selective vasopressin V₂-receptor antagonist. It is only suitable for cases of euvolemic and hypervolemic hyponatremia; an explanation of the condition can be found in a previous article. Hyponatremia can be caused by a number of conditions including Syndrome of Inappropriate Antidiuretic Hormone (SIADH) and heart failure. The specific relationship between hyponatremia and heart failure has been studied extensively. Hyponatremia patients with heart failure often present with an increased circulating neurohormones such as angiotensin II, renin, catecholamines, and vasopressin. When a patient has heart failure, their cardiac output and circulating blood volume decrease causing the body to compensate in order to preserve blood pressure, thus increasing water and sodium retention.

By: Saparja Nag  Mar. 30, 2018

Samsca by Otsuka Pharmaceuticals is a new therapeutic medicine to treat patients with hyponatremia, which is a condition characterized by decreased serum sodium levels relative to the total body water of the patient. Samsca is only intended to be used for cases of hypervolemic and euvolemic hyponatremia. Hypervolemic hyponatremia refers to patients who experience an increase in total body water relative to sodium levels, whereas euvolemic hyponatremic patients maintain roughly the same total body water with decreased sodium levels. Samsca targets two main populations - heart failure patients and patients with SIADH (Syndrome of Inappropriate Secretion of Antidiuretic Hormone). Heart failure patients fall under hypervolemia when edema is present whereas SIADH patients do not experience edema and are categorized as euvolemia. One study found that patients with mild congestion who were given chronic diuretic therapy tolvaptan, the active ingredient in Samsca, saw normalized serum Na+ concentrations for hyponatremic patients and decreased edema.