Abstract
BACKGROUND: Potassium binders mitigate hyperkalemia, allowing patients to maintain their renin-angiotensin-aldosterone-system inhibitor (RAASi) treatment. This study characterized patients treated with first- or second-generation potassium binders, usage patterns and their effectiveness in reducing potassium levels, and changes in RAASi treatment in a Swedish population-based study. METHODS: A National Cohort included patients who had record of a treatment episode with a first-generation or second-generation potassium binder between 2018 and 2022. A Mid-Sweden Cohort included patients from the National Cohort who also had a record of a potassium measurement within the 60 days prior to beginning potassium binder treatment. Comorbidities, prior medication use, persistence with potassium binder treatment, subsequent changes in potassium levels and RAASi treatment were evaluated. Persistence was analyzed using the Kaplan-Meier estimator and changes in potassium levels were assessed using linear mixed-effects models. RESULTS: 23,892 treatment episodes involving 14,235 patients (mean age 70 years, 33% women) were followed in the National Cohort, and 4860 episodes involving 3179 patients (mean age 72 years, 34% women) in the Mid-Sweden Cohort. Patients treated with second-generation potassium binders had more comorbidities and higher median persistence with treatment compared to those on first-generation potassium binders, 112.5 (95% CI:112.5-117.5) vs. 87.5 (95% CI: 87.5-87.5) days in the National Cohort; 165.5 (95% CI: 121.0-198.0) vs. 97.6 (95% CI: 87.5-110.0) days in the Mid-Sweden Cohort. Both first- and second-generation potassium binders reduced potassium levels from baseline by day 15, 5.7 [95% CI: 4.5-6.8] mmol/L to 4.7 [95% CI: 3.6-5.9] mmol/L and 5.5 (95% CI: 4.3-6.7) mmol/L to 4.9 (95% CI: 3.8-6.1) mmol/L, respectively. Dose reduction or discontinuation of renin-angiotensin system inhibitors (RASi) or mineralocorticoid receptor antagonists (MRAs) was found in 31.4% and 47.7%, respectively, within 120 days of initiating therapy. CONCLUSION: Both potassium binders effectively reduced potassium levels, but frequent discontinuation or dose reduction of RAASi therapy were still observed during this period. The adjustments of RAASi therapy, despite the achievement of normokalemia within 15 days, may be premature and warrants careful reconsideration to ensure optimal patient outcomes.