How to manage hyponatremia due to excess water intake?

From the Guidelines

Management of hyponatremia due to excess water intake should primarily focus on fluid restriction, addressing the underlying cause, and correcting sodium levels carefully to prevent complications. For athletes with hyponatremia due to excess water intake, education on appropriate hydration practices and having a hydration plan in place during training is critical 1. Key aspects of management include:

• Identifying athletes at high risk, such as those with excessive fluid consumption, altered renal function, longer race times, female sex, and low body mass index 1
• Monitoring body weight before and after long or simulated events during training to prevent weight gain and excessive weight loss 1
• Rapid identification of symptomatic hyponatremia and provision of oral hypertonic solutions for mild cases or 3% sodium chloride solution for more severe cases 1
• Restricting intravenous hydration in athletes experiencing hyponatremia symptoms and informing local receiving hospitals of the potential presentation 1 In severe cases with neurological symptoms, hospitalization may be necessary for controlled sodium correction using hypertonic saline, with careful monitoring to prevent osmotic demyelination syndrome 1. The goal is to balance the risks of cerebral edema from persistent hyponatremia against rapid correction complications, emphasizing the importance of a careful and controlled approach to managing hyponatremia due to excess water intake.

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. Symptomatic patients, patients likely to require saline therapy during the course of therapy, patients with acute and transient hyponatremia associated with head trauma or postoperative state and patients with hyponatremia due to primary polydipsia, uncontrolled adrenal insufficiency or uncontrolled hypothyroidism were excluded

Management of Hyponatremia due to Excess Water Intake:

• The FDA-approved drug label for tolvaptan 2 does not directly address the management of hyponatremia due to excess water intake, as patients with this condition were excluded from the studies.
• However, the label does provide information on the management of euvolemic or hypervolemic hyponatremia, which may be relevant in some cases.
• Key Points:
  • Tolvaptan is effective in increasing serum sodium levels in patients with euvolemic or hypervolemic hyponatremia.
  • 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 may be necessary in some patients, but it should be avoided if possible during the first 24 hours of therapy to avoid overly rapid correction of serum sodium.

From the Research

Management of Hyponatremia due to Excess Water Intake

Hyponatremia is a condition characterized by low sodium levels in the blood, which can be caused by excess water intake, among other factors. Managing hyponatremia due to excess water intake requires a careful approach to prevent complications.

Principles of Management

• The mainstay of management for hypotonic hyponatremia, which can be caused by excess water intake, is fluid restriction 3.
• Understanding the targets and risks of treatment, as well as continuous monitoring of the patient's clinical status and relevant serum biochemical values, is crucial in the acute treatment of symptomatic hypotonic hyponatremia 3.
• Rapid correction of chronic hypotonic hyponatremia should be avoided to prevent osmotic demyelination syndrome, a condition that can lead to permanent neurological disability or death 3.

Treatment Options

• Vasopressin receptor antagonists (VRAs) are a promising treatment for hyponatremia, particularly for patients with euvolemic and hypervolemic hyponatremia 4, 5, 6.
• VRAs work by inducing urinary dilution, leading to an increase in serum sodium concentration 4.
• The use of VRAs has been shown to be effective in increasing serum sodium levels, with a significant response rate and minimal adverse effects 6.
• However, the optimal indications for the use of VRAs in hyponatremia are still uncertain, and there have been reports of complications resulting from their misuse 5.

Monitoring and Prevention

• Monitoring of changes in serum sodium concentration is essential to guide treatment changes and prevent overcorrection of hyponatremia 7.
• Prevention of osmotic demyelination syndrome should be a prime concern in the treatment of hypotonic hyponatremia, particularly when using VRAs or other treatments that can rapidly correct serum sodium levels 3, 7.