Hyponatremia due to antidepressant medications

Area of Science:

• Geriatric Medicine
• Clinical Pharmacology
• Endocrinology

Background:

• Tricyclic antidepressants (TCAs) are commonly prescribed for elderly patients.
• Drug-induced hyponatremia is a recognized adverse effect, particularly in older adults.
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH) can be triggered by various medications.

Observation:

• An elderly woman presented with severe hyponatremia.
• Her symptoms included lethargy, weakness, and gastrointestinal disturbances.
• The onset of symptoms was insidious, delaying diagnosis.

Findings:

• The patient met the diagnostic criteria for drug-induced SIADH.
• Tricyclic antidepressants were identified as the likely cause of hyponatremia.
• Elderly individuals appear particularly susceptible to this idiosyncratic drug reaction.

Implications:

• Clinicians should consider TCAs as a potential cause of hyponatremia in the elderly.
• Early recognition and management of drug-induced SIADH are crucial.
• This case highlights the importance of medication review in geriatric patients presenting with electrolyte imbalances.