The effect of potassium supplementation and concomitant medications on potassium homeostasis for hospitalized patients.

Purpose: Hospitalized patients receive potassium (K+) supplementation for hypokalemia, with clinicians often estimating a rise in serum K+ levels of 0.1 mEq/L per 10 mEq delivered. However, there is limited evidence to support this expectation. Patients also concomitantly take medications that may alter K+ levels, and it is not known to what degree these may impact interventions to correct K+ levels via supplementation. The objective of this study was to identify the impact of oral and/or intravenous K+ supplementation on serum K+ levels, including the influence of selected concomitant medications, in adult hospitalized patients.

Methods: A single-center, retrospective descriptive study of adult hospitalized patients receiving K+ supplementation at a tertiary hospital between 2021 and 2022 was conducted. Patients were included if they received at least one dose of potassium chloride while admitted to the general medicine ward. The primary outcome was the daily median change in serum K+, normalized per 10 mEq of supplementation administered. The secondary outcome was the impact of selected concomitant medication use on supplement-induced changes in serum K+.

Results: A total of 800 patients and 1,291 daily episodes of K+ supplementation were evaluated. The sample was approximately 53% women, was 78% white, and had a median age of 68 years. The overall daily median change in serum K+ level was 0.05 mEq/L per 10 mEq of supplementation delivered. Patients received a median of 40 mEq of supplementation per day, primarily via the oral route (80.6%). Among the concomitant medications assessed, loop diuretics significantly dampened the impact of K+ supplementation.

Conclusion: Supplementation of K+ in non-critically ill hospitalized patients is variable and dependent on concomitant medication use.