Acute aquaresis by the nonpeptide arginine vasopressin (AVP) antagonist OPC-31260 improves hyponatremia in patients with syndrome of inappropriate secretion of antidiuretic hormon (SIADH). - Saito,T.; Ishikawa,S.; Abe,K.; Kamoi,K.; Yamada,K.; Shimizu,K. (J Clin Endocrinol Metab, 1997)