Clinical question: Are the new potassium binders, patiromer, and sodium zirconium cyclosilicate (SZC) safer than sodium polystyrene sulfonate (SPS)?
Background: Potassium binders were created to reduce the adverse gastrointestinal events, like intestinal necrosis, associated with SPS. However, analyses comparing the safety of SPS with the new binders remain limited.
Study design: Retrospective cohort study
Setting: Veteran Affairs hospitals throughout the U.S.
Synopsis: Using the VA Corporate Data Warehouse database, 3,144,960 admissions (1,461,933 adult patients, ≤30 days) were categorized by: potassium binder use, SPS (30,040; 1%), patiromer (3,750; 0.1%), or SZC (5,520; 0.2%); or no binder (3,105,650; 98.7%). Primary 30-day outcomes were intestinal ischemia or thrombosis and composite major GI adverse outcomes. Intestinal ischemia or thrombosis occurred in 106 (0.35%; aOR, 1.40 [CI, 1.16 to 1.69]) with SPS, 12 (0.32%; aOR, 1.36 [CI, 0.79 to 2.36]) with patiromer, and 24 (0.43%; aOR, 1.78 [CI, 1.21 to 2.63]) with SZC, versus 6,998 (0.23%) without binder. Composite gastrointestinal adverse outcomes occurred in 754 (2.51%; aOR, 1.00 [CI, 0.94 to 1.08]) with SPS, 96 (2.56%; aOR, 1.08 [CI, 0.89 to 1.32]) with patiromer, and 144 (2.61%; aOR, 1.08 [CI, 0.93 to 1.27]) with SZC, versus 75,488 (2.43%) without binder. SPS and SZC were associated with an increased risk of ischemia or thrombosis, but no statistical difference was found between the new binders and SPS. No association was found with composite GI outcomes. Limitations include the observational design (limited data), residual confounding, and limited generalizability.
Bottom line: The risk of intestinal ischemia or thrombosis or major GI adverse events is low among all three potassium binders studied, and this may be a class effect of potassium binders rather than associated with any single medication.
Citation: Holleck JL, et al. Risk of serious adverse gastrointestinal events with potassium binders in hospitalized patients: A national study. J Gen Intern Med. 2024. doi:10.1007/s11606-024-08979-1.
Dr. Martinez is a hospitalist and co-chair of the QI committee in the division of hospital medicine at the University of California Davis Health in Sacramento, Calif.