How to manage hyponatremia in a patient on sertraline (Lustral) and cortisone replacement therapy for adrenal insufficiency?

From the Guidelines

Managing hyponatremia in a patient on sertraline (Lustral) and cortisone replacement therapy for adrenal insufficiency requires careful monitoring and a stepwise approach, prioritizing the optimization of cortisone replacement therapy and addressing potential SSRI-induced SIADH. To manage hyponatremia in this context, first assess the severity of hyponatremia through serum sodium levels and symptoms. For mild to moderate cases (sodium 125-135 mEq/L), fluid restriction to 800-1000 mL/day is recommended while continuing cortisone replacement at the prescribed dose, as inadequate cortisol can worsen hyponatremia 1. Consider adjusting the sertraline dose or switching to an alternative antidepressant with lower risk of SIADH, such as bupropion or mirtazapine, as SSRIs like sertraline can cause hyponatremia through inappropriate ADH secretion. Ensure adequate salt intake (3-5 g/day) and monitor electrolytes weekly until stabilized. For severe hyponatremia (sodium <125 mEq/L) or symptomatic cases, hospitalization may be necessary for controlled sodium correction with hypertonic saline, with a correction rate not exceeding 8 mEq/L in 24 hours to prevent osmotic demyelination syndrome 1. Optimize cortisone replacement therapy, typically hydrocortisone 15-25 mg daily in divided doses, as insufficient cortisol can impair free water excretion, and consider the guidance on corticosteroid management from recent studies 1. Addressing both medication effects and ensuring proper adrenal replacement is essential, as the combination of SSRI-induced SIADH and adrenal insufficiency creates a high-risk situation for persistent hyponatremia. Key considerations include:

• Optimizing cortisone replacement therapy to prevent worsening of hyponatremia
• Managing SSRI-induced SIADH through dose adjustment or alternative antidepressants
• Ensuring adequate salt intake and monitoring electrolytes
• Controlled correction of severe hyponatremia with hypertonic saline in a hospital setting
• Prioritizing recent and high-quality evidence in guiding management decisions 1.

From the FDA Drug Label

Hyponatremia may occur as a result of treatment with SSRIs and SNRIs, including sertraline. In many cases, this hyponatremia appears to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Cases with serum sodium lower than 110 mmol/L have been reported. Elderly patients may be at greater risk of developing hyponatremia with SSRIs and SNRIs Also, patients taking diuretics or who are otherwise volume depleted may be at greater risk (see Geriatric Use). Discontinuation of sertraline should be considered in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which may lead to falls.

To manage hyponatremia in a patient on sertraline (Lustral) and cortisone replacement therapy for adrenal insufficiency, consider the following:

• Discontinuation of sertraline: should be considered in patients with symptomatic hyponatremia
• Appropriate medical intervention: should be instituted to manage hyponatremia
• Monitoring: closely monitor the patient's serum sodium levels and signs and symptoms of hyponatremia, such as headache, difficulty concentrating, and weakness
• Cortisone replacement therapy: may need to be adjusted to ensure that the patient's adrenal insufficiency is adequately managed while also considering the potential effects on hyponatremia 2

From the Research

Managing Hyponatremia in Patients on Sertraline and Cortisone Replacement Therapy

To manage hyponatremia in a patient on sertraline (Lustral) and cortisone replacement therapy for adrenal insufficiency, consider the following steps:

• Identify the underlying cause of hyponatremia, which can be due to various factors including certain medications like sertraline, excessive alcohol consumption, very low-salt diets, and excessive free water intake during exercise 3.
• Categorize the patient according to their fluid volume status: hypovolemic hyponatremia, euvolemic hyponatremia, or hypervolemic hyponatremia 4, 3.
• For hypovolemic hyponatremia, treat with normal saline infusions 3.
• For euvolemic hyponatremia, restrict free water consumption or use salt tablets or intravenous vaptans 3.
• For hypervolemic hyponatremia, manage the underlying cause (e.g., heart failure, cirrhosis) and restrict free water intake 3.

Treatment of Severe Hyponatremia

Severely symptomatic hyponatremia (with signs of somnolence, obtundation, coma, seizures, or cardiorespiratory distress) is a medical emergency and requires immediate attention:

• Use bolus hypertonic saline to reverse hyponatremic encephalopathy by increasing the serum sodium level by 4 mEq/L to 6 mEq/L within 1 to 2 hours, but by no more than 10 mEq/L within the first 24 hours 4, 5.
• Be cautious of overly rapid correction of chronic hyponatremia, which can cause osmotic demyelination, a rare but severe neurological condition 4, 3.

Monitoring and Follow-up

Regular monitoring of serum sodium levels and clinical symptoms is crucial to adjust treatment accordingly:

• Use calculators to guide fluid replacement and avoid overly rapid correction of sodium concentration 3.
• Identify and address the underlying cause of hyponatremia to prevent recurrence 4, 3.