Sequential Drug-Induced Severe Hyponatremia in a Minimally Symptomatic, 81-Year-Old Patient

Background: There have been previous cases of medication-induced hyponatremia with various causative agents reported. Severe hyponatremia, a common medical emergency, can vary widely in its presentation, ranging from seizures and comas to no clinical manifestations.

Case report: An 81-year-old female patient presented to the Emergency Department with history of a fall. She had a known case of hypertension and was recently started on hydrochlorothiazide. When evaluated at the hospital, her sodium level was measured as 106 mmol/L and her clinical symptoms were unremarkable. She was simultaneously diagnosed with a urinary tract infection, for which she was treated with intravenous ciprofloxacin. A few hours after administration, her sodium level fell even further, and she quickly developed symptoms of hyponatremia. After discontinuation of ciprofloxacin and treatment with hypertonic saline (3% NS), she improved and made a full recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: We present an unusual case of minimally symptomatic, severe consecutive multi-medication-induced hyponatremia. As hyponatremia can present asymptomatically, routinely checking sodium levels is recommended, especially when caring for patients who recently experienced a fall or started a thiazide diuretic.