Treatment of chronic hyponatremia and controversy about osmotic demyelination syndrome

Treatment of chronic hyponatremia requires careful diagnostic evaluation of the underlying etiology to adapt the treatment accordingly. Isotonic saline remains the cornerstone for hypovolemic hyponatremia, whereas fluid restriction and loop diuretics are preferred in hypervolemic states. Corticosteroid replacement is the first-line therapy in hyponatremia due to adrenal insufficiency. In the euvolemic syndrome of inappropriate antidiuresis, first-line treatment is fluid restriction, with additional oral urea or vasopressin receptor antagonists as second-line options. Novel strategies such as protein supplementation and SGLT2 inhibitors offer promising adjuncts. The most feared complication of hyponatremia treatment is osmotic demyelination syndrome, with highest risk in patients with severe hyponatremia (≤105 mmol/L), alcoholism, malnutrition, liver disease, or hypokalemia. Current guidelines recommend limiting sodium correction to ≤ 10-12 mmol/L per 24 h (≤8 mmol/L in high-risk patients). Ongoing research aims to investigate future treatment options and to foster evidence on correction limits to improve outcomes in patients with chronic hyponatremia.