Persistent Polyuria in Severe Hyponatremia Secondary to Beer Potomania and Hypokalemia: A Case Report

Multiple electrolyte disorders often coexist in patients with beer potomania, including hypotonic hyponatremia caused by excessive beer consumption and poor solute intake. While hyponatremia is well recognized, its management can be complicated by concurrent hypokalemia and hypomagnesemia, and the impact of other electrolyte imbalances on its treatment remains unclarified. Here, we present a case of severe hyponatremia accompanied by persistent polyuria as a consequence of severe hypokalemia and hypomagnesemia. A 46-year-old man with a history of heavy beer consumption was admitted to the hospital with impaired mental status. Laboratory findings revealed multiple electrolyte disorders, including hyponatremia (111 mmol/L), hypokalemia (1.8 mmol/L), and hypomagnesemia (1.4 mg/dL). Initial treatment with normal saline caused massive diuresis (3,500 mL in six hours) and a rapid rise in serum sodium (119 mmol/L). To prevent overcorrection and subsequent osmotic demyelination, 5% dextrose and vasopressin were administered; however, it failed to adequately control diuresis. As severe hypokalemia and hypomagnesemia were corrected, the antidiuretic response of vasopressin was restored, leading to an improvement in urine output. Vasopressin was tapered and discontinued after serum sodium reached 132 mmol/L on hospital day six. In conclusion, this case highlights the importance of individualized fluid and electrolyte management in beer potomania, especially when antidiuretic hormone responsiveness is impaired, possibly due to hypokalemia and hypomagnesemia.