What is the treatment for hyponatremia (sodium level of 130 mEq/L)?

From the Guidelines

Sodium 130 treatment should prioritize mild fluid restriction and monitoring, as the primary approach is to identify and treat the underlying cause while carefully managing fluid intake, with more aggressive treatments like hypertonic saline reserved for severely symptomatic cases or those with imminent liver transplant, as indicated by the most recent guidelines 1.

Key Considerations

• The goal is to manage mild hyponatremia with a sodium level of 130 mEq/L by identifying and treating the underlying cause.
• Fluid restriction to 1-1.5 liters per day is often recommended as the first step for managing hyponatremia, especially in cases of dilutional hyponatremia when the serum sodium concentration falls below 120-125 mmol/L 1.
• For patients with cirrhosis, the use of hypertonic saline is generally reserved for short-term treatment of those with symptomatic or severe hyponatremia or those with imminent liver transplant, due to the risk of worsening fluid overload and ascites 1.
• Correction of chronic hyponatremia should aim for a rate of increase of serum sodium of 4-6 mEq/L per 24-hour period, not to exceed 8 mEq/L per 24-hour period, to minimize the risk of osmotic demyelination syndrome 1.

Treatment Approaches

• Mild hyponatremia (Na 126-135 mEq/L) in cirrhosis without symptoms may not require specific management apart from monitoring and water restriction 1.
• Water restriction and cessation of diuretics are recommended for moderate hyponatremia (120-125 mEq/L), with more severe restriction and albumin infusion considered for severe hyponatremia (<120 mEq/L) 1.
• Vasopressin receptor antagonists can be used with caution for short-term management of hyponatremia in cirrhosis, but their use should be limited due to potential risks 1.

Monitoring and Safety

• Regular sodium monitoring every 4-6 hours during treatment is essential to ensure safe correction rates and prevent overly rapid correction or osmotic demyelination syndrome 1.
• Multidisciplinary coordinated care is crucial for managing severe hyponatremia, especially in the context of liver transplantation, to mitigate the risk of osmotic demyelination syndrome 1.

From the FDA Drug Label

In two double-blind, placebo-controlled, multi-center studies (SALT-1 and SALT-2), a total of 424 patients with euvolemic or hypervolemic hyponatremia (serum sodium <135 mEq/L) resulting from a variety of underlying causes (heart failure, liver cirrhosis, syndrome of inappropriate antidiuretic hormone [SIADH] and others) were treated for 30 days with tolvaptan or placebo, then followed for an additional 7 days after withdrawal. For patients with a serum sodium of <130 mEq/L or <125 mEq/L, the effects at Day 4 and Day 30 remained significant (see Table 2).

Treatment of Sodium 130:

• Tolvaptan can be used to treat hyponatremia with a serum sodium level of 130 mEq/L.
• The dose of tolvaptan can be increased at 24-hour intervals to 30 mg once daily, then to 60 mg once daily, until either the maximum dose of 60 mg or normonatremia (serum sodium >135 mEq/L) is reached.
• Fluid restriction was to be avoided if possible during the first 24 hours of therapy to avoid overly rapid correction of serum sodium.
• The primary endpoint for these studies was the average daily AUC for change in serum sodium from baseline to Day 4 and baseline to Day 30 in patients with a serum sodium less than 135 mEq/L.
• Compared to placebo, tolvaptan caused a statistically greater increase in serum sodium (p <0.0001) during both periods in both studies.
• For patients with a serum sodium of <130 mEq/L, the effects at Day 4 and Day 30 remained significant, with a change in average daily serum [Na+] AUC baseline to Day 4 (mEq/L) of 4.8 (3.0) and to Day 30 of 7.9 (4.1) 2.

From the Research

Sodium 130 Treatment

• Sodium level of 130 mEq/L is considered mild hyponatremia 3
• Mild symptoms of hyponatremia include nausea, vomiting, weakness, headache, and mild neurocognitive deficits 3
• Treatment of hyponatremia is based on the underlying cause and whether the patient is hypovolemic, euvolemic, or hypervolemic 3, 4

Treatment Approaches

• Hypovolemic hyponatremia is treated with normal saline infusions 3
• Euvolemic hyponatremia is treated by restricting free water consumption or using salt tablets or intravenous vaptans 3, 5, 6
• Hypervolemic hyponatremia is treated primarily by managing the underlying cause and free water restriction 3, 4

Medications

• Vaptans are nonpeptide vasopressin antagonists that can be effective in treating euvolemic and hypervolemic hyponatremia 5, 6
• Vaptans are particularly useful in treating hypervolemic hyponatremia associated with severe congestive heart failure or chronic liver failure 6
• Hypertonic saline infusion is reserved for patients with severely symptomatic hyponatremia 3, 4

Important Considerations

• Overly rapid correction of sodium concentration can cause osmotic demyelination syndrome 3, 4
• Treatment should not be delayed while a diagnosis is pursued, and the underlying cause of hyponatremia should be identified if possible 3