Hyperkalemia is a serious medical condition that often manifests in patients with
chronic kidney disease and
heart failure. Renin-angiotensin-aldosterone system inhibitors are known to improve outcomes in these disease states but can also cause
drug-induced
hyperkalemia. New therapeutic options exist for managing
hyperkalemia in these patients which warrant evidence-based evaluation.
AIM: Current treatment options to enhance
potassium excretion are SPS and
loop diuretics, which are complicated by ambiguous efficacy and known toxicities.
Patiromer and ZS9 are new agents designed to address this treatment gap. Both unabsorbable compounds bind
potassium in the gastrointestinal (GI) tract to facilitate fecal excretion. The capacity to bind other medications in the GI tract infers high
drug-drug interaction potential, which has been demonstrated with
patiromer but not yet investigated with ZS9 or SPS. Phase II and III clinical trials of
patiromer and ZS9 demonstrated clear evidence of a dose-dependent
potassium-lowering effect and the ability to initiate, maintain, or titrate renin-angiotensin-aldosterone system inhibitors. There is limited evidence base for SPS: two small clinical trials indicated
potassium reduction in chronic
hyperkalemia. All agents may cause adverse GI effects, although they are less frequent with ZS9. Concerns remain for SPS to cause rare GI damage.
Electrolyte abnormalities occurred with
patiromer and SPS, whereas
urinary tract infections,
edema, and corrected QT-interval prolongations were reported with ZS9.
CONCLUSION:
Patiromer and ZS9 have improved upon the age-old standard SPS for the treatment of
hyperkalemia. Additional research should focus on
drug-drug interactions in patients on multiple medications, incidence of rare adverse events, and use in high-risk populations.