Real-World Evaluation of Patiromer for the Treatment of Hyperkalemia in Hemodialysis Patients

Abstract

Introduction: Patiromer is a potassium (K⁺) binding polymer indicated for treating hyperkalemia. Among patients receiving chronic hemodialysis (HD), this study aimed to identify patient characteristics associated with patiromer initiation, describe patiromer utilization, and analyze serum K⁺ pre- and post-patiromer initiation.

Methods: In a retrospective cohort study, using electronic health record data from a large dialysis provider in the United States (study period: December 21, 2015, to December 20, 2016), HD patients were included who had a medication order for patiromer, sodium polystyrene sulfonate (SPS), or laboratory evidence of hyperkalemia (no K⁺ binder [NoKb] cohort). The index date was the first order for patiromer/SPS, or the first K⁺ ≥5.0 mEq/l (NoKb cohort), respectively. Using multivariable logistic regression, we identified patient characteristics associated with patiromer initiation. We evaluated patiromer utilization using Kaplan-Meier methodology and proportion of days covered. Serum K⁺ concentrations were assessed pre- versus post-patiromer initiation.

Results: Study cohorts included 527 (patiromer), 852 (SPS), and 8747 (NoKb) HD patients. Median follow-up was 141 days. Patiromer initiators were 2.6 times more likely to have had multiple prior episodes of hyperkalemia (odds ratio [OR]: 2.6; 95% confidence interval [CI]: 1.8-3.7). Most (61%) commenced patiromer on 8.4 g once daily; 60% of patients' first patiromer order remained open after 180 days. Statistically significant reductions in K⁺, averaging approximately -0.5 mEq/l, were observed post-patiromer initiation (48% pre-patiromer vs. 22% post-patiromer had K⁺ ≥6.0 mEq/l [P < 0.001]).

Conclusion: Patiromer initiators receiving chronic hemodialysis had comparatively more severe, uncontrolled baseline hyperkalemia. Medication order data show long-term patiromer use was associated with significantly reduced K⁺.

Keywords: hemodialysis; hyperkalemia; patiromer.

Figure 1

Baseline characteristics independently associated with patiromer initiation versus patients in the sodium polystyrene sulfonate (SPS) cohort. GOF, goodness of fit; HD, hemodialysis; K, potassium.

Figure 2

Mean serum potassium and 95% confidence interval pre- versus post-patiromer initiation. *Using the last potassium value in each monthly interval for each included patient.

Figure 3

Mean potassium change pre- versus post-patiromer initiation: all patiromer initiators (a); restricted to patiromer initiators with a baseline potassium ≥5.0 mEq/l (b). *P values and 95% confidence intervals (CIs) were estimated using the paired t test (H₀: Δ = 0). The paired t test compared the last K⁺ value in the 3-month pre-patiromer to the last K⁺ value in each 30-day follow-up interval post-patiromer initiation. K⁺, potassium.

Figure 4

Proportion of patients with potassium ≥6.0 mEq/l pre- versus post-patiromer initiation: all patiromer initiators (a); restricted to patiromer initiators with a baseline potassium ≥5.0 mEq/l (b). *P values were derived from the McNemar test, a within-subject z-test of equality of proportions for correlated data. This paired statistical test compares the proportion of patients with a K⁺ value ≥6.0 mEq/l pre-patiromer initiation versus post-patiromer initiation. The last K⁺ value in the 3-month pre-patiromer interval was compared with the last K⁺ value in each monthly follow-up interval. CI, confidence interval; K⁺, potassium.