What is the treatment for hyponatremia (low sodium)?

From the Guidelines

Treatment of low sodium (hyponatremia) in patients with cirrhosis should prioritize a cautious approach to correction, aiming for a goal 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 ameliorate the risk of ODS, as recommended by the American Association for the Study of Liver Diseases in 2021 1. When managing hyponatremia in cirrhosis, the severity of the condition guides the treatment approach.

• For mild hyponatremia (Na 126-135 mEq/L) without symptoms, no specific management apart from monitoring and water restriction is required 1.
• For moderate hyponatremia (120-125 mEq/L), water restriction to 1,000 mL/day and cessation of diuretics is recommended, while severe hyponatremia (<120 mEq/L) may require a more severe restriction of water intake with albumin infusion 1. Key considerations in the treatment of hyponatremia include:
• The use of vasopressin receptor antagonists can raise serum sodium but should be used with caution for short-term treatment (≤30 days) 1.
• Hypertonic saline is reserved for short-term treatment of patients with symptomatic or severe hyponatremia or those with imminent liver transplant (LT) 1.
• Multidisciplinary coordinated care may mitigate the risk of ODS in patients with severe hyponatremia undergoing LT 1.

From the FDA Drug Label

Tolvaptan tablets are indicated for the treatment of clinically significant hypervolemic and euvolemic hyponatremia (serum sodium <125 mEq/L or less marked hyponatremia that is symptomatic and has resisted correction with fluid restriction), including patients with heart failure and Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Treatment for low sodium: Tolvaptan is indicated for the treatment of clinically significant hypervolemic and euvolemic hyponatremia. The usual starting dose for tolvaptan tablets is 15 mg administered once daily without regard to meals.

• Increase the dose to 30 mg once daily, after at least 24 hours, to a maximum of 60 mg once daily, as needed to achieve the desired level of serum sodium.
• Patients should be in a hospital for initiation and re-initiation of therapy to evaluate the therapeutic response and because too rapid correction of hyponatremia can cause osmotic demyelination resulting in serious neurologic sequelae 2.
• In two double-blind, placebo-controlled, multi-center studies (SALT-1 and SALT-2), tolvaptan caused a statistically greater increase in serum sodium (p <0.0001) during both periods in both studies 2.

From the Research

Treatment of Low Sodium (Hyponatremia)

• Hyponatremia is defined as a serum sodium level of less than 135 mEq/L and can be categorized as mild, moderate, or severe based on the sodium concentration 3, 4.
• The treatment of hyponatremia depends on the underlying cause, severity of symptoms, and volume status of the patient (hypovolemic, euvolemic, or hypervolemic) 3, 4, 5.
• For patients with severe symptoms, such as delirium, confusion, or seizures, emergency treatment with 3% hypertonic saline is recommended to rapidly increase serum sodium levels 3, 4.
• In patients with hypovolemic hyponatremia, treatment involves normal saline infusions to correct the volume deficit 3.
• Euvolemic hyponatremia is treated by restricting free water consumption or using salt tablets or intravenous vaptans 3, 6.
• Hypervolemic hyponatremia is primarily treated by managing the underlying cause (e.g., heart failure, cirrhosis) and restricting free water intake 3, 4.
• Vasopressin receptor antagonists, such as conivaptan and tolvaptan, are effective in treating hypervolemic and euvolemic hyponatremia, but their use is limited by high acquisition costs and potential adverse effects 6, 7.
• The goal of treatment is to increase serum sodium levels by 8-12 mEq/L within the first 24 hours, while avoiding overly rapid correction, which can cause osmotic demyelination syndrome 3, 4, 6.

Key Considerations

• Identifying the underlying cause of hyponatremia is crucial for effective treatment 3, 4, 5.
• Clinicians should be aware of the potential risks and benefits of different treatment options, including the use of hypertonic saline, vasopressin receptor antagonists, and fluid restriction 3, 4, 6, 7.
• Regular monitoring of serum sodium levels and patient symptoms is essential to adjust treatment and prevent complications 3, 4, 5.