From the Guidelines
The treatment for an 87-year-old female presenting to the ED with severe hyponatremia (sodium of 119 mEq/L) should focus on determining if she has neurological symptoms requiring urgent correction, and for symptomatic patients, administer 100-150 mL of 3% hypertonic saline over 10-20 minutes, which can be repeated if symptoms persist, as recommended by the most recent guidelines 1.
Initial Management
The initial management should focus on determining the cause of hyponatremia and assessing the patient's symptoms and volume status.
- For symptomatic patients with seizures or altered mental status, administer 100-150 mL of 3% hypertonic saline over 10-20 minutes, which can be repeated if symptoms persist.
- For asymptomatic or mildly symptomatic patients, a slower correction is safer, aiming to increase sodium by no more than 6-8 mEq/L in the first 24 hours and no more than 10-12 mEq/L in 48 hours to prevent osmotic demyelination syndrome, as suggested by 1 and 1.
Fluid Management
- Fluid restriction to 800-1000 mL/day is appropriate for SIADH.
- If the patient has volume depletion, isotonic saline (0.9% NaCl) should be administered, as recommended by 1 and 1.
- Hypertonic sodium chloride administration should be reserved for those who are severely symptomatic with acute hyponatraemia, especially if a transplant is imminent, as stated in 1.
Monitoring and Underlying Cause
- Frequent monitoring of serum sodium (every 2-4 hours initially) is essential to guide therapy.
- The underlying cause must be identified and treated, whether it's SIADH, heart failure, liver disease, adrenal insufficiency, or medication-induced hyponatremia, as this will determine long-term management beyond the acute correction, as emphasized by 1, 1, and 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) 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.
The treatment for an 87-year-old female presenting with a sodium level of 119 is tolvaptan, starting with a dose of 15 mg once daily, which can be increased to 30 mg once daily after at least 24 hours, and up to a maximum of 60 mg once daily as needed to achieve the desired level of serum sodium 2.
- Key considerations:
- Initiate and re-initiate in a hospital to monitor serum sodium closely.
- Avoid too rapid correction of hyponatremia (> 12 mEq/L/24 hours) to prevent osmotic demyelination.
- Monitor serum sodium and neurologic status, especially during initiation and after titration 2.
- Important warnings:
- Tolvaptan is not for use in patients with autosomal dominant polycystic kidney disease (ADPKD) outside of the FDA-approved REMS.
- Tolvaptan can cause liver injury, so it should not be administered for more than 30 days 2.
From the Research
Treatment of Hyponatremia
The treatment of hyponatremia depends on the type of hyponatremia and its underlying cause. For an 87-year-old female presenting with a sodium level of 119, the following treatment options may be considered:
- Fluid restriction can be an effective therapy in dilutional hyponatremia, although poor compliance and the burdensome nature of the restrictions are important considerations 3.
- Tolvaptan, an oral vasopressin receptor antagonist, can increase serum sodium concentrations by increasing electrolyte-free water excretion and is supported by clinical trial evidence in patients with hypervolaemic or euvolaemic hyponatraemia below 125 mmol/L 3, 4.
- Vaptans, a class of pharmaceuticals developed for the treatment of hypervolemic and euvolemic forms of hyponatremia, can be used to treat hyponatremia associated with severe congestive heart failure or chronic liver failure, as well as euvolemic hyponatremia associated with the syndrome of inappropriate antidiuretic hormone (SIADH) 4, 5.
- Hypertonic saline infusion may be used in cases of acute, severe, and symptomatic hyponatremia, although its effects can vary unpredictably from patient to patient 4.
Special Considerations
When treating hyponatremia, special attention is needed to correct serum sodium levels at the appropriate rate, especially in chronic hyponatremia, in order to avoid the osmotic demyelination syndrome 6. Additionally, the use of vaptans is affected by regulatory restrictions of chronic therapy due to safety concerns and the non-subsidized cost of treatment 3.
Underlying Causes
It is essential to identify and address the underlying cause of hyponatremia, which can be multifactorial in the elderly population 6. Common causes of hyponatremia in older people include medications used to treat chronic disease, particularly thiazide or thiazide-like drugs, or drugs acting on the central nervous system 3.