Introduction and Aims: Patiromer is an FDA-approved nonabsorbed potassium (K)-binding polymer that uses calcium rather than sodium (Na) as the counter ion for exchange to avoid Na loading. In addition to binding K, patiromer may also bind Na in the gastrointestinal (GI) tract, potentially further minimizing concerns regarding volume overload in patients with heart failure (HF) or chronic kidney disease (CKD). Here we report changes in urine (u) Na excretion as a measure of GI Na absorption in healthy subjects treated with patiromer.
Methods: Healthy adults were admitted to a research unit and placed on an 8-day rotating controlled diet (K ~4.7 g/d, Na ~2.5 g/d) from admission (day −1) until discharge (day 20). Subjects were randomized to receive placebo or patiromer at doses up to 50.4 g/d (in divided TID dosing for 8 days [days 12-19]); N=32. After 4 equilibration days on the controlled diet, 24-hr urine samples were analyzed for Na on baseline days 5-11 and compared with on-treatment days 13-19.
Results: Patiromer significantly decreased uK in a dose dose-related manner (previously reported) and resulted in a dose-related decrease in mean uNa (p=0.009 for trend across patiromer doses) (Table). As uNa reflects Na absorption in the steady state, these data support the hypothesis that patiromer binds and eliminates Na as well as K via the GI tract.
SO008 Table 1:
Conclusions: Urine Na excretion is decreased in a dose-related manner in healthy subjects receiving patiromer. These data suggest that patiromer binds Na as well as K in the GI tract, which should reduce the risk of volume overload in patients with HF and/or CKD receiving patiromer for treatment of hyperkalemia.
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