Table 5.
Similarities and differences among sodium polystyrene sulfonate, patiromer and sodium zirconium cycosilicate in pharmacological characteristics and side-effect profile.
| Characteristic | SPS | Patiromer | ZS-9 |
|---|---|---|---|
| FDA approval | Yes (1958) | Yes (2015) | Pending |
| Chemical structure | Non-absorbed, organic, sodium-containing resin | Non-absorbed, organic, sodium-free polymer | Non-absorbed, insoluble, inorganic, sodium-containing crystalline silicate |
| Mechanism of action | Nonspecific cation binding in exchange for sodium | Nonspecific cation binding in exchange for calcium | Selective potassium binding in exchange for sodium and hydrogen |
| Administration | Oral or rectal | Oral | Oral |
| Formulation | Suspension in sorbitol or dissolvable powder | Oral suspension | Oral suspension |
| Location of action | Colon | Distal colon predominantly | Entire intestinal track |
| Onset of action | 1–2 hours | 7 hours | 1 hour |
| Dosing | •15–60 g/day orally • 30–50 g/day rectally |
8.4 – 25.2 g daily | 5–10 g daily, depending on FDA recommendations |
| Drug interactions | •Cation donating agents may interfere with the potassium-lowering efficacy of SPS. • Intestinal obstruction when aluminum hydroxide was combined with SPS. • Possible decreased absorption of co-administered lithium and thyroxin. • Co-administration with non-absorbable cation-donating antacids and laxatives was associated with systemic alkalosis. |
• Reduced systemic exposure of coadministered ciprofloxacin, metformin, and levothyroxine.57 • No interaction when patiromer and these drugs were taken 3 hours apart.57 |
• No significant drug-drug interactions involving ZS-9 in currently available clinical studies |
| Commonly reported adverse reactions | •GI disorders (i.e., constipation, nausea, vomiting, diarrhea) • Hypernatremia • Hypokalemia • Metabolic alkalosis • Volume overload |
•GI disorders (i.e., constipation, nausea, vomiting, diarrhea, flatulence) • Hypokalemia • Hypomagnesemia |
• GI disorders (i.e., constipation, nausea, vomiting, diarrhea) • Hypokalemia • Edema |
| Serious adverse events | Colonic necrosis | None | None |
Abbreviations: FDA; Food and Drug Administration; GI= gastrointestinal; sK= serum potassium; SPS= sodium polystyrene sulfonate; ZS-9= sodium zirconium cycosilicate;