Current therapeutic options for hyponatremia: indications, limitations, and confounding variables.

The arginine vasopressin receptor antagonists, also known as the vaptans, are a new class of agents that address some of the unmet medical needs of patients with hyponatremia. Traditional therapies, including diuretics, fluid restriction, and saline infusions, have variable effects, potential toxicities, and concerns with patient adherence. Furthermore, these therapies are not specific to the underlying pathophysiology causing the hyponatremia. The recently approved arginine vasopressin receptor antagonists, however, target the underlying abnormal release of arginine vasopressin that is very likely at the core of the pathophysiology. Management of hyponatremia requires balancing the benefits of therapeutic intervention to restore normal serum sodium concentrations against the potential risks. Additional clinical experience is needed to develop reliable criteria for determining which patients should be treated with these agents. However, the data available indicate that this new class of drugs can favorably affect serum sodium concentration and clinical outcomes in patients with hypervolemic and euvolemic hyponatremia.