Drug-Induced Electrolyte Disturbances in Older Adults Presenting to the Emergency Department: Mechanisms, Recognition and Prevention

Many older adults attending the emergency department (ED) take medications that interfere with water and electrolyte balance. This narrative review, based on a structured PubMed/MEDLINE search covering January 2016 to September 2026, summarizes evidence on drug-associated disorders of sodium, potassium, magnesium and calcium in older ED patients. Thiazides, antidepressants, antiepileptic drugs, antipsychotics, proton pump inhibitors and desmopressin are associated with hyponatremia; with thiazides, the risk peaks in the first weeks of treatment and is highest in women aged 80 years or older. Lithium can cause nephrogenic diabetes insipidus, which may persist after discontinuation and cause hypernatremia when water intake is inadequate. Renin–angiotensin–aldosterone system inhibitors, mineralocorticoid receptor antagonists, trimethoprim and non-steroidal anti-inflammatory drugs predispose to hyperkalemia, particularly in chronic kidney disease; diuretics and proton pump inhibitors are associated with hypokalemia and hypomagnesemia; and denosumab can cause severe hypocalcemia in advanced kidney disease. Most of this evidence is observational, and drugs usually act together with comorbidities, acute illness and other medications. We propose a severity-based ED algorithm integrating medication history, laboratory, electrocardiographic and volume assessment (including point-of-care ultrasound) to guide stabilization, drug adjustment, safe correction and disposition. ED-based medication safety programs reduce inappropriate prescribing, but their effect on electrolyte-related outcomes remains unproven.