Sodium Polystyrene Sulfonate
There are no consistent data on use of SPS and its long-term efficacy. In one randomized trial of 33 CKD patients, sorbitol-free SPS was superior to placebo in reducing serum K+ (between-group difference: 1.04 mEq/l; P < 0.001) over a 7-day period without a significant difference in gastrointestinal adverse events between the groups. However, the small number of patients and short duration of this trial are not sufficient to support long-term use of SPS in patients with hyperkalemia. The drug binds K+ in exchange for Na+ and can lead to volume overload and requires caution when used in patients with congestive heart failure, severe hypertension, edema, or CKD (Table 2). In addition, SPS has been associated with various adverse events including colonic necrosis, which is a life-threatening complication, associated with a 33% mortality rate. This complication most commonly occurs in postoperative patients, kidney transplant patients who are immunosuppressed, or in the setting of delayed intestinal transit as with ileus or opioid use. Because of these issues and concerns, SPS use is typically restricted to the inpatient setting. In a recent population-level cohort study, the risk of hospitalization for adverse gastrointestinal events within 30 days of initiation of SPS increased 1.9-fold compared with nonuse Given these considerations, chronic use of SPS is not a viable strategy to prevent hyperkalemia and enable long-term use of RAASi therapy.
Curr Opin Nephrol Hypertens. 2020;29(1):29-38. © 2020 Lippincott Williams & Wilkins