Drug-Resistant Hyponatremia after Escitalopram Intake: A Series of Two Case Reports

The consumption of new selective serotonin reuptake inhibitors (SSRIs) is raising dramatically especially in European countries. It contributes to occurrence of clinically important drug side effects. One of which can be hyponatremia. We present two case reports of 85-year-old and 84-year-old women who developed hyponatremia after escitalopram administration. We hypothesize that in both cases hyponatremia was connected with antidepressants administration. However, due to multiple comorbidities and polypharmacy it is often impossible to establish the exact mechanism of hyponatremia. Moreover, it is crucial to distinguish subtypes of drug-induced syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH), such as SSRI-induced SIADH, reset osmostat SIADH, thiazide-associated hyponatremia, thiazide-induced hyponatremia, mineralocorticoid responsive hyponatremia of older adults, in order to properly diagnose and treat geriatric patients. Administration of antidepressants or thiazides should be followed by a regular monitoring of serum sodium level.