SODIUM POLYSTYRENE SULFONATE
| SODIUM POLYSTYRENE SULFONATE (pol-ee-stye'reen) Kayexalate, SPS Suspension Classifications: electrolyte and water balance agent; cation exchange; Therapeutic: cation exchange Pregnancy Category: C |
Availability
15 g/60 mL suspension; 100 mg/g powder
Action
Sulfonic cation-exchange resin that removes potassium from body by exchanging sodium ion for potassium, particularly in large intestine; potassium-containing resin is then excreted through the bowel. Small amounts of other cations such as calcium and magnesium may be lost during treatment.
Therapeutic Effect
Removes potassium from body by exchanging sodium ion for potassium through the large intestine.
Uses
Hyperkalemia.
Contraindications
Patients with hypokalemia; hypersensitivity to Kayexalate; GI obstruction; hypocalcemia, hypokalemia; pregnancy (category C), lactation.
Cautious Use
Older adults; acute or chronic kidney failure; low birth weight infants; neonates with reduced gut; patients receiving digitalis preparations; patients who cannot tolerate even a small increase in sodium load (e.g., CHF, severe hypertension, and marked edema).
Route & Dosage
| Hyperkalemia Adult: PO 15 g suspended in 70% sorbitol or 20–100 mL of other fluid 1–4 times/d PR 30–50 g/100 mL 70% sorbitol q6h as warm emulsion high into sigmoid colon Child: PO Calculate appropriate amount on exchange rate of 1 mEq of potassium per gram of resin and suspend in 70% sorbitol or other appropriate solution (usual dose: 1 g/kg q6h) PR 1 g/kg q2–6h |
Administration
Oral- Give as a suspension in a small quantity of water or in syrup. Usual amount of fluid ranges from 20–100 mL or approximately 3–4 mL/g of drug.
- Use warm fluid (as prescribed) to prepare the emulsion for enema.
- Administer at body temperature and introduce by gravity, keeping suspension particles in solution by stirring. Flush suspension with 50–100 mL of fluid; then clamp tube and leave it in place.
- Urge patient to retain enema at least 30–60 min but as long as several hours if possible.
- Irrigate colon (after enema solution has been expelled) with 1 or 2 qt flushing solution (non-sodium containing). Drain returns constantly through a Y-tube connection.
- Store remainder of prepared solution for 24 h; then discard.
Adverse Effects (≥1%)
GI: Constipation, fecal impaction (in older adults); anorexia, gastric irritation, nausea, vomiting, diarrhea (with sorbitol emulsions). Metabolic: Sodium retention, hypocalcemia, hypokalemia, hypomagnesemia.Interactions
Drug: antacids, laxatives containing calcium or magnesium may decrease potassium exchange capability of the resin.Pharmacokinetics
Absorption: Not absorbed systemically. Onset: Several hours to days. Metabolism: Not metabolized. Elimination: In feces.Nursing Implications
Assessment & Drug Effects
- Lab tests: Determine serum potassium levels daily throughout therapy. Monitor acid–base balance, electrolytes, and minerals in patients receiving repeated doses.
- Serum potassium levels do not always reflect intracellular potassium deficiency. Observe patient closely for early clinical signs of severe hypokalemia (see Appendix F). ECGs are also recommended.
- Consult physician about restricting sodium content from dietary and other sources since drug contains approximately 100 mg (4.1 mEq) of sodium per gram (1 tsp, 15 mEq sodium).
Patient & Family Education
- Check bowel function daily. Usually, a mild laxative is prescribed to prevent constipation (common adverse effect). Older adult patients are particularly prone to fecal impaction.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug