Objective To compare and contrast the efficacy and safety of patiromer and sodium zirconium cyclosilicate (ZS-9) in the treatment of hyperkalemia. Design A systematic review and meta-analysis of phase II and III clinical trial data was completed. Patients or Participants Eight studies (2 phase II and 4 phase III trials with 2 subgroup analyses) were included in the qualitative analysis whereas six studies (2 phase II and 4 phase III trials) were included in the meta-analysis. Measurements and Results There was significant heterogeneity in the meta-analysis with an I2 value ranging from 80.6–99.6%. A random-effects meta-analysis was applied for all endpoints. Each clinical trial stratified results by hyperkalemia severity and dosing; therefore, these were considered separate treatment groups in the meta-analysis. For patiromer, there was a significant −0.70mEq/L (95% confidence interval [CI] −0.48 to −0.91mEq/L) change in potassium at 4 weeks. At day 3 of patiromer treatment, potassium change was −0.36mEq/L (range of standard deviation: 0.07 to 0.30). The primary endpoint for ZS-9-- change in potassium at 48 hours-- was −0.67mEq/L (95% CI −0.45 to −0.89mEq/L). By 1 hour after ZS-9 administration, change in potassium was −0.17mEq/L (95% CI −0.05 to −0.30). Analysis of pooled adverse effects from these trials indicates that patiromer was associated with more gastrointestinal upset (7.6% constipation, 4.5% diarrhea) and electrolyte depletion (7.1% hypomagnesemia), whereas ZS-9 was associated with adverse effects of urinary tract infections (1.1%) and edema (0.9%). Conclusion Patiromer and ZS-9 represent significant pharmacologic advancements in the treatment of hyperkalemia. Both agents exhibited statistically and clinically significant reductions in potassium for the primary endpoint of this meta-analysis. Given the adverse effect profile and the observed time dependent effects, ZS-9 may play more of a role in treating acute hyperkalemia.

No abstract

IntroductionHyperkalemia 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.AimThe objective of this article was to review the efficacy and safety evidence for patiromer, sodium zirconium cyclosilicate (ZS9), and sodium polystyrene sulfonate (SPS) for the treatment of hyperkalemia.Evidence reviewCurrent 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.ConclusionPatiromer 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.

Limited antiretrovirals are currently available for the management of multidrug-resistant (MDR) HIV-1 infection. Ibalizumab, a recombinant humanized monoclonal antibody, represents the first novel agent for HIV-1 management in over a decade and is the first monoclonal antibody for the treatment of MDR HIV-1 infection in combination with other forms of antiretroviral therapy in heavily treatment-experienced adults who are failing their current antiretroviral regimen. Ibalizumab demonstrates a novel mechanism of action as a CD4-directed postattachment inhibitor and has a favorable pharmacokinetic profile that allows for a dosing interval of every 14 days after an initial loading dose. Clinical studies have demonstrated reasonably substantial antiretroviral activity with ibalizumab among a complex patient population with advanced HIV-1 infection who are receiving an optimized background regimen, where limited therapeutic options exist. Ibalizumab was well tolerated in clinical trials, and the most common adverse effects included diarrhea, nausea, dizziness, fatigue, pyrexia, and rash. Resistance to ibalizumab has also been observed via reduced expression or loss of the potential N-linked glycosylation sites in the V5 loop of the envelope glycoprotein 120. The mechanism of action, pharmacokinetic parameters, efficacy, and safety of ibalizumab present an advance in the management of MDR HIV-1 infection. Future studies and postmarketing experience will further determine longer-term clinical efficacy, safety, and resistance data for ibalizumab.