Reported Cases of Hyponatremia Associated with Lexapro (Escitalopram)
Based on published literature, there are extremely few documented cases of escitalopram-induced hyponatremia—only approximately 14-15 reported cases in the medical literature as of 2018, making this a rare but potentially serious adverse effect. 1
Case Report Evidence
The published literature reveals the following specific cases:
Individual case reports document 14 cases of escitalopram-associated SIADH (syndrome of inappropriate antidiuretic hormone secretion) leading to hyponatremia prior to 2018 1
Two cases were reported together in 2008, involving women aged 65 and 81 years who developed SIADH after initiating escitalopram 10 mg/day and citalopram 20 mg/day respectively 2
One case in 2017 described a 54-year-old hypertensive female who developed severe hyponatremia with seizures after a short course of escitalopram 3
One case in 2018 involved a 93-year-old female presenting with generalized tonic-clonic seizures due to severe escitalopram-induced SIADH 1
One case in 2006 reported SIADH development after 4 weeks of escitalopram treatment, with improvement following discontinuation 4
Comparative Context with Related SSRIs
While escitalopram cases are rare, citalopram (the parent compound) has more extensive documentation, with one review identifying 14 cases in published literature plus 28 cases spontaneously reported to the Australian Drug Reaction Advisory Committee (ADRAC) 5. This suggests escitalopram may have a lower incidence than citalopram, though underreporting remains possible.
High-Risk Patient Characteristics
Among documented cases across SSRIs including escitalopram:
- 79% of symptomatic cases occurred in patients older than 70 years 5
- 74% occurred in women 5
- 84% of cases were detected during the first month of treatment with the SSRI 5
- Polymedication and concomitant use of thiazide diuretics or other psychotropic drugs may precipitate or augment hyponatremia development 5
Clinical Implications
The rarity of reported cases (14-15 in published literature) does not diminish clinical significance, as severe hyponatremia can lead to seizures, coma, and potentially death if not properly managed 6, 7. The actual incidence may be higher due to underreporting, particularly of mild asymptomatic cases 5.
Close monitoring of serum sodium is essential, particularly in elderly patients during the first month of escitalopram therapy, as this represents the highest-risk period 5, 3. Regular electrolyte monitoring should be considered standard practice when prescribing escitalopram to high-risk populations 3.