Which of the following is NOT an appropriate initial therapy for hyponatremia with severe neurologic symptoms?

• A. 3% hypertonic saline
• B. Isotonic saline
• C. 3% hypertonic saline with furosemide
• D. Demeclocycline

Answer: (D)

When hyponatremia presents with severe neurologic symptoms, the priority is to rapidly raise the serum sodium to reduce brain edema and prevent deterioration. The best initial move is to administer hypertonic saline (3% NaCl) in a controlled way, so a small, careful bolus or drip is given while monitoring sodium levels and neurologic status. Sometimes a loop diuretic like furosemide is added to enhance free water excretion and help prevent overly rapid correction.

Isotonic saline, while useful in hypovolemic hyponatremia, usually does not correct sodium quickly enough to relieve severe brain symptoms and can worsen edema in some cases. It’s not the optimal initial choice when neurologic impairment is present.

Demeclocycline is not appropriate for initial management of acute, symptomatic hyponatremia. It works by causing nephrogenic diabetes insipidus, thereby inhibiting water reabsorption, but its onset is delayed by days, making it unsuitable for urgent correction. It’s reserved for chronic SIADH in select situations, not for acute life-threatening hyponatremia.