Which statement best describes vasopressin receptor antagonists (vaptans) in clinical use?

Which statement best describes vasopressin receptor antagonists (vaptans) in clinical use?

• A. They are first-line therapy in outpatients
• B. They are used only in hypovolemic hyponatremia
• C. They have demonstrated mortality benefit in SIADH
• D. They require in-hospital use and are expensive, with no proven better outcomes

Answer: (D)

Vaptans work by blocking vasopressin receptors, which promotes excretion of free water (aquaresis) and raises serum sodium without rapidly losing electrolytes. Because this can correct sodium levels quickly and carries risks such as overly rapid correction and, with long-term use, potential liver injury, their use is reserved for hospitalized patients with hyponatremia who require careful monitoring. They are expensive, and large studies have not shown a clear survival or major clinical outcome benefit in SIADH or other hyponatremias, so they are not a routine outpatient or first-line therapy. This combination of the need for inpatient monitoring, cost, and lack of proven mortality or major outcome advantage best describes their clinical use.

Vaptans work by blocking vasopressin receptors, which promotes excretion of free water (aquaresis) and raises serum sodium without rapidly losing electrolytes. Because this can correct sodium levels quickly and carries risks such as overly rapid correction and, with long-term use, potential liver injury, their use is reserved for hospitalized patients with hyponatremia who require careful monitoring. They are expensive, and large studies have not shown a clear survival or major clinical outcome benefit in SIADH or other hyponatremias, so they are not a routine outpatient or first-line therapy. This combination of the need for inpatient monitoring, cost, and lack of proven mortality or major outcome advantage best describes their clinical use.