A retrospective observational study of potentially drug-associated hyperkalemia among hospitalized adult patients

Abstract Hyperkalemia is a common but potentially serious electrolyte imbalance, and hospitalized patients are at a higher risk due to relatively severe illness and need for multiple medications. Data on burden and characteristics of potentially drug-associated hyperkalemia in the general inpatient population, particularly in India, is limited. This retrospective observational study aimed to evaluate the burden of such cases among hospitalized adult patients and to describe their clinicodemographic characteristics. Inpatients admitted at a tertiary care hospital in India between January 2023 and December 2024 were studied. Patients ≥ 18 years of age with hyperkalemia, as determined based on the laboratory reports, were included in the study. The severity of hyperkalemia was determined using the European Society of Cardiology (ESC; mild 5.1–5.4, moderate 5.5–6.0, severe > 6.0 mEq/L) and European Resuscitation Council (ERC; mild, 5.5–5.9, moderate 6.0–6.4, severe ≥ 6.5 mEq/L) guidelines. The age, sex, duration of hospitalization, comorbid conditions, and suspect drugs (medications with known effects on potassium homeostasis) prescribed were assessed among these severity categories. A p-value < 0.05 was considered statistically significant. Of the 13,038 adult inpatients, 943 (7.23%) met the ESC criteria for hyperkalemia and 476 (3.65%) met the ERC criteria. The median age was approximately 60 years, with a slight female preponderance among those with severe hyperkalemia, and the duration of hospitalization was approximately 6 days. Hypertension and diabetes mellitus were the most prevalent morbidities, and beta blockers and nonsteroidal antiinflammatory drugs were the most common suspect medications identified, with the percentage of patients receiving potassium supplements increasing in those with severe hyperkalemia. In multivariable analysis, type 2 diabetes mellitus remained associated with higher odds of severe hyperkalemia after adjustment for the available covariates. The apparent inverse association observed with renin-angiotensin-aldosterone system inhibitor use varied according to kidney disease status and should not be interpreted as a protective effect, given the potential influence of index-event bias and other sources of confounding. In conclusion, hyperkalemia is a frequent electrolyte abnormality among hospitalized patients. Patients with hyperkalemia were frequently older, had multiple comorbidities, and were commonly exposed to one or more medications known to influence potassium homeostasis. These findings highlight the importance of careful medication review and awareness of polypharmacy, particularly in patients receiving multiple potassium-altering medications. The choice of hyperkalemia classification system substantially influenced the prevalence estimates and severity distributions and should be carefully considered when comparing findings across studies.