From the FDA Drug Label
Removal of excess free body water increases serum osmolality and serum sodium concentrations. All patients treated with tolvaptan, especially those whose serum sodium levels become normal, should continue to be monitored to ensure serum sodium remains within normal limits If hypernatremia is observed, management may include dose decreases or interruption of tolvaptan treatment, combined with modification of free-water intake or infusion.
High sodium treatment with tolvaptan may involve monitoring serum sodium levels and managing hypernatremia by adjusting the dose or interrupting treatment, as well as modifying free-water intake or infusion 1.
- Key considerations include:
- Monitoring serum sodium levels
- Managing hypernatremia
- Adjusting treatment as needed to prevent excessive serum sodium concentrations.
From the Research
High sodium treatment, also known as hypertonic saline therapy, is recommended for patients with severe hyponatremia or increased intracranial pressure, with the goal of raising serum sodium by no more than 8-10 mEq/L in the first 24 hours and 18 mEq/L in 48 hours to avoid osmotic demyelination syndrome, as supported by the most recent and highest quality study 2.
Key Considerations
- The standard approach involves administering 3% hypertonic saline solution at an initial rate of 1-2 mL/kg/hour, with careful monitoring of serum sodium levels, neurological status, and fluid balance.
- For acute symptomatic hyponatremia, a bolus of 100-150 mL of 3% saline over 10-20 minutes may be given, repeatable up to 2-3 times if symptoms persist.
- The controlled sodium increase is crucial because too rapid correction can damage brain cells by causing them to shrink too quickly, potentially leading to permanent neurological damage.
Diagnosis and Management
- Hyponatremia is defined by a serum sodium level of less than 135 mEq/L and most commonly results from water retention.
- Symptoms and signs of hyponatremia range from mild and nonspecific (such as weakness or nausea) to severe and life-threatening (such as seizures or coma).
- The approach to managing hyponatremia should consist of treating the underlying cause, and urea and vaptans can be effective treatments for the syndrome of inappropriate antidiuresis and hyponatremia in patients with heart failure.
Monitoring and Adjustments
- Frequent monitoring of serum sodium levels (every 2-4 hours initially), neurological status, and fluid balance is essential during treatment.
- The treatment approach should be adjusted based on the patient's response, and overly rapid correction of chronic hyponatremia should be avoided to prevent osmotic demyelination syndrome, as highlighted in 2.