The European Commission sanctioned Otsuka Pharmaceutical’ s Samsca™ for the treatment of hyponatremia secondary to syndrome of inappropriate antidiuretic hormone secretion in adults. This once-daily oral V2-vasopressin receptor antagonist is reportedly the first such drug available in Europe.
Samsca is designed to promote aquaresis, i.e., the excretion of electrolyte-free water rather than diuresis, in which both sodium and water are released.
European approval follows FDA clearance of Samsca in May as the only oral selective vasopressin antagonist for the treatment of patients with clinically significant hypervolemic and euvolemic hyponatremia including patients with heart failure, cirrhosis, and SIADH. This is marked by serum sodium of less than 125 mEq/L or lower hyponatremia that is symptomatic and has resisted correction with fluid restriction.