Use of sodium polystyrene sulfonate (SPS) may increase the risk of dying from gastrointestinal injury, investigators reported at the American Society of Nephrology’s Kidney Week 2021.
Among 63,323 patients on hemodialysis (HD) from the 2002-2018 Dialysis Outcomes and Practice Patterns Study (DOPPS), 7107 (11.2%) received the potassium binder SPS. Physician-determined fatal gastrointestinal events occurred in 895 patients (1.41%), including 150 (2.11%) prescribed SPS and 1.33% who did not take the drug. Fatal events included mesenteric infarction/ischemic bowel, perforation of bowel, and perforation of a peptic ulcer.
After propensity score matching, investigators found a significant 30% increased risk for fatal gastrointestinal events among SPS users vs nonusers, Ana Cecilia Farfan Ruiz, MD, MSc, of Ottawa Hospital Research Institute in Canada, reported for her team. The investigators also examined facility-level data. Compared with dialysis facilities with no SPS use, facilities with 1-10%, 11-20%, 21-30%, and more than 30% SPS use had 24%, 82%, 11%, and 46% increased risks for fatal gastrointestinal events, respectively. All results were significant except for facility-level SPS use of 21-30%.
Approximately 1 in 128 patients on dialysis who received SPS experienced a fatal gastrointestinal event, Dr Ruiz reported. Younger and male patients had significant 2.4- and 1.7-fold increased risks, respectively. The presence of peripheral vascular disease and the absence of coronary artery disease were both significantly associated with a 1.5-fold increased risk. No diuretic use and a dialysis vintage of longer than 4 years were significantly associated with a 1.4-fold and 1.7-fold increased risk for fatal gastrointestinal events, respectively. Country of origin and a more recent era also correlated with increased risk. The mean age of the DOPPS cohort was 65.4 years and 61.6% were male. Countries participating in DOPPS included Australia/New Zealand, Belgium, France, Italy, Japan, Spain, Sweden, and others.
“Our results add to the growing concerns of SPS use as a therapeutic agent for the management of hyperkalemia,” Dr Ruiz and colleagues stated.
Their previous study published in JAMA Internal Medicine in 2019 found higher risk of gastrointestinal injury in a cohort of 20,020 SPS users. Other research published in Nephrology Dialysis Transplantation reached similar conclusions.
The current study was limited by a lack of information on medication adherence, type of administration, duration of use, and dosage.
Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Farfan Ruiz AC, Malick R, Rhodes E, et al. Fatal gastrointestinal events with sodium polystyrene sulfonate use in hemodialysis: an international cohort study. Presented at: Kidney Week 2021, November 2-7, 2021. Poster PO0849.