Should You Have Your Serum Sodium Checked for Hyponatremia?
Yes, you should have your serum sodium level checked, as you are at elevated risk for SSRI-induced hyponatremia given your age (62 years), female sex, and recent dose increase of escitalopram. 1
Why You Are at Risk
You have multiple risk factors that place you at higher risk for developing hyponatremia while taking escitalopram:
- Age over 60 years: Elderly patients are at significantly greater risk of developing hyponatremia with SSRIs, with the FDA label specifically warning about this risk 1
- Female sex: Women are at higher risk for SSRI-induced hyponatremia compared to men 2, 3, 4
- Recent dose increase: You increased from a lower dose to 20 mg just two weeks ago, and the risk of hyponatremia is highest during the first few weeks of treatment or after dose changes 2, 3, 5, 4
- Duration on escitalopram: While you've been on the medication for 6 months total, the recent dose escalation resets your risk window 6, 5
The Clinical Significance
Escitalopram can cause hyponatremia through the syndrome of inappropriate antidiuretic hormone secretion (SIADH), with cases documented as low as 110 mmol/L. 1 This is not a trivial concern:
- The FDA label explicitly states that elderly patients may be at greater risk, and that discontinuation should be considered in patients with symptomatic hyponatremia 1
- Symptoms can range from headache, confusion, and weakness to severe manifestations including seizures, coma, and death 1
- The frequency of hyponatremia in elderly female patients receiving SSRIs has been estimated as high as 8 per 1,000 patients 4
Timing of Monitoring
The highest risk period is within the first few weeks of starting treatment or increasing the dose. 2, 3, 5, 4 Since you increased your dose just two weeks ago, you are currently in this high-risk window.
- Most cases of SSRI-induced hyponatremia occur within the first month of treatment or dose adjustment 6, 5
- One study showed hyponatremia developing 2 months after starting citalopram (a closely related medication) 2
- The effect is not dose-dependent, meaning it can occur at any dose 6
What Should Be Done
Baseline serum sodium measurement should be obtained now, given your risk profile and recent dose increase. 2, 6
- Check serum sodium level as soon as possible (within the next few days) 2, 6
- If the sodium level is normal, consider repeat monitoring in 2-4 weeks, as you remain in the high-risk period 2, 6
- Monitor for symptoms including headache, confusion, weakness, unsteadiness, nausea, or difficulty concentrating 1
Important Context About Your Diuretic Status
While you are not currently on diuretics, this is actually protective—concomitant diuretic use significantly increases the risk of SSRI-induced hyponatremia. 1, 4 The FDA label specifically warns that "patients taking diuretics or who are otherwise volume depleted may be at greater risk" 1. However, your other risk factors (age and sex) remain significant even without diuretic use.
What Happens If Hyponatremia Is Found
If hyponatremia is detected:
- Mild asymptomatic hyponatremia may be managed with close monitoring 7
- Symptomatic hyponatremia requires discontinuation of escitalopram and appropriate medical intervention 1
- Sodium levels typically return to normal within days to weeks after SSRI withdrawal 3, 5
- In most cases, the hyponatremia is reversible when the medication is stopped 1, 3
Common Pitfall to Avoid
Do not assume that because you tolerated a lower dose for 6 months without problems, you are safe at the higher dose. 6 Hyponatremia can develop at any point during treatment and is not dose-dependent 6. The recent dose increase to 20 mg resets your risk window, making monitoring particularly important now.