In SIADH, which is the recommended first-line treatment?

In SIADH, which is the recommended first-line treatment?

• A. Increase fluid intake
• B. IV hypotonic saline
• C. Fluid restriction less than 1000 ml per day
• D. Administer steroids

Answer: (C)

In SIADH, excess ADH causes the body to retain free water, leading to dilutional hyponatremia while the patient remains euvolemic. The most effective first step is to limit water intake to reduce ongoing water retention and allow serum sodium to rise gradually. A common target is restricting fluids to about 800–1000 mL per day. This approach addresses the root issue—too much free water—without introducing more sodium or altering other hormones. Hypertonic saline or other therapies may be reserved for severe symptoms or refractory cases, but the initial, recommended management is fluid restriction under 1 liter per day.

In SIADH, excess ADH causes the body to retain free water, leading to dilutional hyponatremia while the patient remains euvolemic. The most effective first step is to limit water intake to reduce ongoing water retention and allow serum sodium to rise gradually. A common target is restricting fluids to about 800–1000 mL per day. This approach addresses the root issue—too much free water—without introducing more sodium or altering other hormones. Hypertonic saline or other therapies may be reserved for severe symptoms or refractory cases, but the initial, recommended management is fluid restriction under 1 liter per day.