Abstract
A 90-year-old male with hypertension and diabetes presented with acute limb weakness and dizziness. Laboratory tests revealed severe hyponatremia (Na(+) 111.6 mmol/L) and rhabdomyolysis (CK 1771 U/L), which occurred after the recent initiation of irbesartan-hydrochlorothiazide for edema. The patient's symptoms resolved, and the laboratory test results normalized after the drug was discontinued and the patient's sodium concentration was corrected with hypertonic saline. This case highlights hydrochlorothiazide-induced hyponatremia as a rare trigger for rhabdomyolysis in elderly patients with comorbidities.