Effect of oral AVP receptor antagonists OPC-21268 and OPC-31260 on congestive heart failure in conscious dogs

Oral administration of selective arginine vasopressin AVP V1 receptor antagonist OPC-21268 causes an increase in cardiac output and renal function while that of AVP V2 receptor antagonist OPC-31260 results in an increase in plasma renin activity, plasma levels and serum sodium concentration of AVP in dogs with congestive heart failure. AVP V1 receptor antagonist does not affect serum electrolytes and hormones while AVP V2 receptor antagonist induces water diuresis. Combined administration of both the receptor antagonists triggers additive metabolic and renal responses and supra-additive hemodynamic responses.