<p>Sodium Polystyrene Sulfonate is a non-absorbed, cation exchange polymer that contains a sodium counterion. Sodium Polystyrene Sulfonate increases fecal potassium excretion through binding of potassium in the lumen of the gastrointestinal tract. Binding of potassium reduces the concentration of free potassium in the gastrointestinal lumen, resulting in a reduction of serum potassium levels. The practical exchange ratio is 1 mEq K per 1 gram of resin.<br />
<br />
As the resin passes along the intestine or is retained in the&nbsp;colon&nbsp;after administration by&nbsp;enema, the sodium ions are partially released and are replaced by potassium ions. This action occurs primarily in the&nbsp;large intestine, which excretes potassium ions to a greater degree than does the&nbsp;small intestine. The efficiency of this process is limited and unpredictably variable.</p>