Sodium polystyrene sulfonate is a sulfonated cation-exchange resin that is used for the removal of excess potassium.
Sodium polystyrene sulfonate is used in the treatment of hyperkalemia. The drug aids in the removal of excess potassium from the body and should be considered an adjunct to other measures such as restriction of electrolyte intake, control of acidosis, and a high caloric diet. Before therapy is instituted, the cause of hyperkalemia should be determined and eliminated if possible. Because the action of the resin is slow, sodium polystyrene sulfonate alone may be insufficient (effective lowering of serum potassium may occur within hours to days) to rapidly correct severe hyperkalemia, including that associated with states of rapid tissue breakdown (e.g., burns, renal failure).108 Treatments that facilitate shift of potassium into cells, such as administration of sodium bicarbonate and/or dextrose (with or without insulin), and/or other treatments (e.g., a calcium salt) are indicated in patients with hyperkalemia evidenced by conduction defects (widening of the QRS complex) or arrhythmias. If hyperkalemia is severe, other definitive measures, including dialysis, should be considered.108 Sodium polystyrene sulfonate is most useful when hyperkalemia is not life-threatening or when other measures have reduced the dangers of hyperkalemia. The drug should not be used as an emergency treatment for life-threatening hyperkalemia.116
Reconstitution and Administration
Sodium polystyrene sulfonate is administered orally or rectally.
Oral administration of sodium polystyrene sulfonate should be separated from oral administration of other drugs by at least 3 hours, and the separation time should be increased to 6 hours for patients with gastroparesis.115,116 (See Drug Interactions: Effects on GI Absorption of Drugs.)
When sodium polystyrene sulfonate is administered orally, each 1 g of the powdered resin should be reconstituted in 3-4 mL of water or a syrup and given as a suspension;116 usually 20-100 mL of fluid is used. Alternatively, the resin may be administered orally as a commercially available suspension. The suspension should be shaken well prior to administration.108 Sodium polystyrene sulfonate suspension also may be introduced into the stomach via a tube or the powdered resin or suspension may be mixed with the patient's food. The drug should not be mixed with foods or liquids that contain a large amount of potassium such as bananas or orange juice. Full precautions to prevent aspiration (e.g., placing and keeping the patient in an upright position during administration) should be observed.116
When sodium polystyrene sulfonate is administered rectally as a retention enema, each dose of the powdered resin is administered in 100-200 mL of an aqueous vehicle, such as 1% methylcellulose, 10% dextrose, or water, which has been warmed to body temperature. Although a somewhat thicker suspension may be used, care should be taken that a paste, which would greatly reduce the exchange surface and be particularly ineffective if deposited in the rectal ampulla, is not formed. Alternatively, 120-200 mL of a commercially available suspension may be administered as a retention enema, after the suspension has been warmed to body temperature. The suspension should be shaken well prior to administration.108 After an initial cleansing enema, a soft, large (French 28) rubber tube should be inserted about 20 cm into the rectum, with the tip well into the sigmoid colon, and taped in place. The extemporaneously prepared suspension of the resin, kept in suspension by stirring, or the commercially available suspension is then administered rectally by gravity feed. The tube may then be flushed with 50-100 mL of fluid, clamped, and left in place. If back leakage occurs, the hips should be elevated on pillows or a knee-chest position assumed. The suspension is retained in the colon for at least 30-60 minutes or for several hours if possible, after which the colon is irrigated with a non-sodium-containing solution at body temperature to remove the resin. Returns should be drained constantly through a Y-tube connection.108 Care should be taken to ensure that adequate volumes of non-sodium-containing cleansing enemas are administered.108 Approximately 2 L of irrigating solution may be needed to adequately flush out the resin. Proper removal of the resin is particularly important if sorbitol is used (administration of sorbitol is not recommended).108 Some clinicians believe that the preferred method of rectal administration is to place the resin in a sealed dialysis bag and insert the bag into the rectum.
The dosage and duration of sodium polystyrene sulfonate therapy must be individualized and depend on daily assessment of total body potassium. (See Cautions: Precautions and Contraindications.)
The usual adult oral dosage of sodium polystyrene sulfonate is 15 g (approximately 4 level teaspoonfuls of the powder or 60 mL of the commercially available suspension) 1-4 times daily (average 15-60 g daily).
Sodium polystyrene sulfonate may also be given rectally as a retention enema (see Rectal Administration, in Dosage and Administration: Reconstitution and Administration) in adult doses of 30-50 g (120-200 mL of the commercially available suspension) every 6 hours.108,116
Reduced dosage is recommended in infants and small children.108 Pediatric dosage may be based on the fact that 1 g of the resin binds approximately 1 mEq of potassium. Oral administration is contraindicated in neonates.108 Some manufacturers also state that rectal administration is contraindicated in neonates and premature infants.108 (See Cautions: Pediatric Precautions.)
Sodium polystyrene sulfonate may cause some degree of gastric irritation. Anorexia, nausea, vomiting, and constipation may occur, especially if large doses are given. Large doses of the drug may cause fecal impaction, especially in geriatric patients. If clinically important constipation occurs, therapy with sodium polystyrene sulfonate should be discontinued until normal bowel movements resume; administration of magnesium hydroxide laxatives or sorbitol is not recommended.108,116 (See Drug Interactions.) Occasionally, the resin causes diarrhea.
Intestinal necrosis, which may be fatal, and other serious adverse GI events (bleeding, ischemic colitis, perforation) have been reported in patients receiving sodium polystyrene sulfonate.108,109,110,116 Most cases have occurred in patients receiving sorbitol concomitantly; many of the patients had risk factors for adverse GI events (e.g., prematurity, history of intestinal disease or surgery, hypovolemia, renal insufficiency or failure).108,110,116 (See Cautions: Precautions and Contraindications.) Although a causal relationship to the resin and/or sorbitol has not been established, some clinicians have suggested that studies in uremic rats implicate sorbitol rather than sodium polystyrene sulfonate as being principally responsible for intestinal necrosis. However, the occurrence of GI injury in patients receiving sodium polystyrene sulfonate without sorbitol and the presence of sodium polystyrene sulfonate crystals in injured segments of the GI tract have led others to suggest that the resin itself may be pathogenic.110
In a systematic review of 58 cases of adverse GI events associated with sodium polystyrene sulfonate use, 71% of patients received the resin in combination with sorbitol, and 77% received the resin orally; 71% of patients had a history of chronic kidney disease or end-stage renal disease requiring dialysis, 16% had undergone prior solid organ transplantation, and 28% had undergone a recent surgical procedure.110 The colon was the most common site of injury (76% of patients); injuries in more proximal segments of the GI tract often were accompanied by colonic injury.110 Histolopathologic examination of GI specimens revealed transmural necrosis in 62% and ulceration in 48% of patients; sodium polystyrene sulfonate crystals were detected in injured segments of the GI tract in 90% of patients.110 Common presenting symptoms included abdominal pain and distension, GI bleeding, nausea and vomiting, and diarrhea; the median time from initiation of therapy to onset of symptoms was 2 days.110 The mortality rate in this series of patients was 33%, with 94% of the deaths occurring in patients with evidence of colonic necrosis.110
Hypokalemia and clinically important sodium retention may occur in patients receiving sodium polystyrene sulfonate therapy. Since the cation-exchange action of sodium polystyrene sulfonate is not totally selective for potassium, increased excretion of other cations occurs. (See Pharmacology.) Hypocalcemia and other electrolyte disturbances may occur.
Acute bronchitis and bronchopneumonia following aspiration of sodium polystyrene sulfonate particles have been reported.116
Precautions and Contraindications
Patients receiving sodium polystyrene sulfonate should be monitored for electrolyte (e.g., calcium, magnesium, potassium) abnormalities. Serum potassium concentrations should be determined frequently within each 24-hour period during therapy;108,116 the duration of treatment with the resin must be determined individually for each patient. Because intracellular potassium deficiency is not always reflected by serum potassium concentrations, electrocardiograms and the clinical condition of the patient also should be closely monitored. ECG abnormalities seen with hypokalemia include lengthened QT intervals; widened, flat, or inverted T waves; and prominent U waves. Cardiac abnormalities, including premature atrial, nodal, or ventricular contractions and supraventricular and ventricular tachycardias, may also occur. Early signs of severe hypokalemia include a pattern of irritable confusion, delayed thought processes, and muscle cramps. Marked hypokalemia can also be manifested by severe muscle weakness and occasionally frank paralysis. The risk of precipitating hypokalemia-induced cardiotoxic effects of cardiac glycosides should be considered when sodium polystyrene sulfonate is administered to patients receiving these glycosides.
Because of the potential for intestinal necrosis and other serious adverse GI events (bleeding, ischemic colitis, perforation), sodium polystyrene sulfonate should be used only in patients with normal bowel function.108,116 Use of the drug should be avoided in patients at risk for developing constipation or impaction (e.g., those with a history of fecal impaction, chronic constipation, inflammatory bowel disease, ischemic colitis, vascular intestinal atherosclerosis, previous bowel resection, or bowel obstruction) and in postoperative patients who have not had a bowel movement following surgery.108,116 Because most of the reported cases of intestinal necrosis or other serious adverse GI events occurred in patients who received sorbitol concomitantly with sodium polystyrene sulfonate, concomitant administration of sorbitol is not recommended.108,109,116 Most commercially available suspensions of sodium polystyrene sulfonate have been reformulated without sorbitol;108,112 however, preparations in a 33% sorbitol vehicle remain commercially available.111,112 Therapy with sodium polystyrene sulfonate should be discontinued if constipation occurs.108,116
Precautions (e.g., placing and keeping the patient in an upright position during oral administration) should be taken to prevent aspiration.116 Patients with an impaired gag reflex, altered level of consciousness, or predisposition to regurgitation may be at an increased risk of aspirating sodium polystyrene sulfonate following oral administration.116
Because administration of sodium polystyrene sulfonate may represent a clinically important sodium load (see Chemistry and Stability: Chemistry), the resin should be administered cautiously to patients whose sodium intake must be restricted, such as those with heart failure, hypertension, or edema. In these patients, compensatory restriction of sodium intake from other sources may be indicated.
In vitro studies have shown that sodium polystyrene sulfonate can bind to other drugs, which may decrease the extent of absorption of these drugs following concomitant oral administration.115,116 Other oral drugs should be administered at least 3 hours before or 3 hours after oral administration of sodium polystyrene sulfonate, and the separation time should be increased to 6 hours for patients with gastroparesis.115,116 (See Drug Interactions: Effects on GI Absorption of Drugs.)
Sodium polystyrene sulfonate is contraindicated in patients with hypokalemia, those with obstructive bowel disease, and those with known hypersensitivity to sodium polystyrene sulfonate resins.108,116 The drug also is contraindicated in neonates with decreased gut motility.116 Oral administration of sodium polystyrene sulfonate is contraindicated in neonates; some manufacturers state that use of the drug (oral or rectal administration) is contraindicated in neonates and premature infants.108 (See Cautions: Pediatric Precautions.)
Efficacy of sodium polystyrene sulfonate in pediatric patients has not been established.108,116
Sodium polystyrene sulfonate is contraindicated in neonates with reduced gut motility.116 Premature or low-birthweight infants may have an increased risk of adverse GI effects (e.g., intestinal necrosis) with sodium polystyrene sulfonate use.116 Some manufacturers state that use of the drug is contraindicated in premature infants.108
Oral administration of sodium polystyrene sulfonate is contraindicated in neonates.108 The drug should be administered rectally in children and neonates with particular caution, since excessive dosages or inadequate dilution may result in impaction of the resin;108,116 care should be taken to ensure an adequate volume of non-sodium-containing cleansing enemas after rectal administration.108 Some manufacturers state that rectal administration is contraindicated in neonates.108
Large doses of sodium polystyrene sulfonate may cause fecal impaction in geriatric patients.108
Animal reproduction studies have not been performed with sodium polystyrene sulfonate.108 Sodium polystyrene sulfonate is not absorbed systemically following oral or rectal administration, and use in pregnant women is not expected to result in fetal risk.116
Breast-feeding is not expected to result in risk to infants of sodium polystyrene sulfonate-treated women because the drug is not absorbed systemically.116
Effects on GI Absorption of Drugs
In vitro studies have shown that sodium polystyrene sulfonate may bind to other drugs (e.g., amlodipine, amoxicillin, furosemide, metoprolol, phenytoin, warfarin).115,116 Binding of sodium polystyrene sulfonate to other oral drugs could reduce GI absorption of the concomitantly administered agents and result in loss of efficacy when administration times are close to those of sodium polystyrene sulfonate.115,116 Therefore, other oral drugs should be administered at least 3 hours before or 3 hours after oral administration of sodium polystyrene sulfonate.115,116 Patients with gastroparesis or other conditions resulting in delayed gastric emptying may require a 6-hour separation.115,116 FDA states that the recommended spacing interval is based on the expected time for either sodium polystyrene sulfonate or the other drug to pass through the stomach.115 Clinical response and/or blood concentrations of the drugs should be monitored whenever possible.105,116 The manufacturers state that sodium polystyrene sulfonate may decrease absorption of lithium and thyroxine.108,116
Sodium polystyrene sulfonate, when given orally with cation-donating antacids and laxatives such as magnesium hydroxide or calcium carbonate, has been reported to cause metabolic alkalosis in patients with renal disease. Magnesium hydroxide and calcium carbonate neutralize gastric hydrochloric acid and form the ionizable compounds magnesium chloride and calcium chloride. Upon entry into the small intestine, the magnesium and calcium ions react with bicarbonate and form magnesium carbonate and calcium carbonate, both of which are insoluble. However, sodium polystyrene sulfonate prevents this reaction by binding with the magnesium and calcium before they react with bicarbonate. This results in a loss of hydrogen ions from the stomach without a loss of bicarbonate ions from the intestine and, subsequently, in metabolic alkalosis. Rectal use of sodium polystyrene sulfonate may avoid this reaction.
In one study in patients with renal impairment (i.e., creatinine clearance ranging from 10-60 mL/minute), increases in plasma CO2 concentration and in plasma and urinary pH were reported following concomitant use of sodium polystyrene sulfonate and calcium- or magnesium-containing antacids. Severe systemic alkalosis and a tonic-clonic seizure reportedly occurred in one patient with chronic hypocalcemia secondary to renal failure who received magnesium hydroxide and sodium polystyrene sulfonate concomitantly. In one patient with impaired renal function and chronic metabolic acidosis, the systemic alkalosis produced by concomitant use of sodium polystyrene sulfonate and magnesium hydroxide was used to therapeutic advantage.
Simultaneous oral administration of cation-donating antacids and laxatives with sodium polystyrene sulfonate may also reduce the resin's potassium exchange capability. Although there are no controlled studies to date, some clinicians have observed resistance to the potassium-lowering effect of sodium polystyrene sulfonate in hyperkalemic patients receiving magnesium hydroxide; response to sodium polystyrene sulfonate was reportedly restored when magnesium hydroxide was discontinued.
One case of small bowel obstruction resulting from aluminum hydroxide concretion has been reported to be associated with concurrent sodium polystyrene sulfonate therapy. However, the patient was receiving 720-1440 mL of aluminum hydroxide gel per day, and intestinal obstruction has been reported to occur with doses of aluminum hydroxide gel as low as 120 mL per day without concurrent administration of the resin.
Sodium polystyrene sulfonate and calcium- or magnesium-containing antacids or laxatives should be used with caution, especially in patients with renal impairment. The manufacturer warns that magnesium hydroxide should not be used as a laxative for the treatment of sodium polystyrene sulfonate-induced constipation.
Concomitant use of sorbitol with sodium polystyrene sulfonate may result in intestinal necrosis and is not recommended.108,116 (See Cautions: GI Effects and Cautions: Precautions and Contraindications.)
Sodium polystyrene sulfonate-induced hypokalemia may increase toxic effects of cardiac glycosides on the heart (e.g., ventricular arrhythmias, AV nodal dissociation).108
Sodium polystyrene sulfonate is a cation-exchange resin that releases sodium in exchange for other cations. Following oral administration, sodium is released from the resin in exchange for hydrogen ions in the acidic environment of the stomach. As the resin passes through the intestines, hydrogen cations exchange with those cations that are in greater concentrations and the cationically modified resin is excreted in the feces. Because of the relatively high concentration of potassium present in the large intestine, conversion of the resin to the potassium form occurs principally at this site. Following rectal administration of sodium polystyrene sulfonate, sodium ions are partially released from the resin in exchange for other cations present. In clinical use, much of the exchange capacity of sodium polystyrene sulfonate is utilized for cations other than potassium such as calcium, magnesium, iron, organic cations, lipids, steroids, and proteins. Thus, although 1 g of the resin has an in vitro exchange capacity of about 3.1 mEq of potassium, an in vivo exchange capacity greater than 1 mEq of potassium per g of resin is not likely.
Sodium polystyrene sulfonate is a sulfonated cation-exchange resin prepared in the sodium phase and used for the removal of excess potassium. Each gram of the resin has an in vitro exchange capacity of about 3.1 mEq (range: 2.81-3.45 mEq) of potassium. Sodium polystyrene sulfonate occurs as a cream to light brown, fine powder that is odorless and tasteless and is insoluble in water. Each gram of the powdered resin contains approximately 4.1 mEq of sodium.
Sodium polystyrene sulfonate is commercially available as the powder or as a suspension. The commercially available suspension is an amber-colored, cherry-flavored suspension of the resin; the vehicle contains purified water, propylene glycol, magnesium aluminum silicate, sucralose, citric acid, flavoring agent, and parabens as a preservative.108 Each 100 mL of the commercially available suspension contains 25 g of sodium polystyrene sulfonate and 114 mEq of sodium.108 The drug also remains available as a light brown, cherry-flavored suspension in a 33% sorbitol vehicle that contains alcohol, purified water, propylene glycol, magnesium aluminum silicate, sodium saccharin, flavoring agent, and parabens as a preservative.111,112 (See Drug Interactions: Sorbitol.)
Sodium polystyrene sulfonate powder and commercially available suspensions should be stored in well-closed containers at a temperature of 20-25°C, but some preparations may be exposed to temperatures ranging from 15-30°C.108,111,116,117 If repackaged, the commercially available suspensions should be refrigerated and used within 14 days of repackaging.108,111
Sodium polystyrene sulfonate should not be heated because changes in the exchange properties of the resin may occur. The manufacturers of the powdered resin state that extemporaneous suspensions of the resin should be freshly prepared and should not be stored for more than 24 hours. However, an extemporaneously prepared 25% suspension of the powdered resin in water using a combination of 0.5% carboxymethylcellulose and 0.3% magnesium aluminum silicate as suspending agents was reportedly stable (i.e., easily redispersed, minimal sedimentation) for at least 30 days.
Additional Information
The American Society of Health-System Pharmacists, Inc. represents that the information provided in the accompanying monograph was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are advised that decisions regarding use of drugs are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and that the information contained in the monograph is provided for informational purposes only. The manufacturer's labeling should be consulted for more detailed information. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information contained in the monograph is not a substitute for medical care.
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Oral or Rectal | Powder, for suspension | |||
Sodium Polystyrene Sulfonate Powder | ||||
Suspension | 1.25 g/5 mL* | Kionex® | Perrigo | |
Sodium Polystyrene Sulfonate Suspension | ||||
SPS® |
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
AHFS® Drug Information. © Copyright, 1959-2025, Selected Revisions April 10, 2024. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, MD 20814.
Only references cited for selected revisions after 1984 are available electronically.
100. Lillemoe KD, Romolo JL, Hamilton SR et al. Intestinal necrosis due to sodium polystyrene (Kayexalate) in sorbitol enemas: clinical and experimental support for the hypothesis. Surgery . 1987; 101:267-72. [PubMed 3824154]
101. Wootton FT, Rhodes DF, Lee WM et al. Colonic necrosis with Kayexalate-sorbitol enemas after renal transplantation. Ann Intern Med . 1989; 111:947-9. [PubMed 2817643]
102. Arvanitakis C, Malek G, Uehling D et al. Colonic complications after renal transplantation. Gastroenterology . 1973; 64:533-8. [PubMed 4144776]
103. Burnett RJ. Sodium polystyrene-sorbitol enemas. Ann Intern Med . 1990; 112:311-2. [PubMed 2297214]
104. Shepard KV. Cleansing enemas after sodium polystyrene sulfonate enemas. Ann Intern Med . 1990; 112:711. [PubMed 2334084]
105. Food and Drug Administration. FDA drug safety communication: FDA requires drug interaction studies with potassium-lowering drug Kayexalate (sodium polystyrene sulfonate). Rockville, MD; 2015 Oct 22. From FDA website. Accessed 2016 Mar 3. [Web]
108. West-Ward Pharmaceuticals. Sodium polystyrene sulfonate suspension prescribing information. Eatontown, NJ; 2016 May.
109. McGowan CE, Saha S, Chu G et al. Intestinal necrosis due to sodium polystyrene sulfonate (Kayexalate) in sorbitol. South Med J . 2009; 102:493-7. [PubMed 19373153][PubMedCentral]
110. Harel Z, Harel S, Shah PS et al. Gastrointestinal adverse events with sodium polystyrene sulfonate (Kayexalate) use: a systematic review. Am J Med . 2013; 126:264.e9-24.
111. CMP Pharma. Sodium polystyrene sulfonate suspension prescribing information. Farmville, NC; 2017 Jan.
112. Sterns RH, Rojas M, Bernstein P et al. Ion-exchange resins for the treatment of hyperkalemia: are they safe and effective?. J Am Soc Nephrol . 2010; 21:733-5. [PubMed 20167700]
115. Food and Drug Administration. FDA drug safety communication: FDA recommends separating dosing of potassium-lowering drug sodium polystyrene sulfonate (Kayexalate) from all other oral drugs. Silver Spring, MD; 2017 Sep 6. From FDA website. Accessed 2018 Mar 12. [Web]
116. Perrigo. Kionex® (sodium polystyrene sulfonate) powder for suspension prescribing information. Minneapolis, MN; 2017 Aug.
117. CMP Pharma. Sodium polystyrene sulfonate powder for suspension prescribing information. Farmville, NC; 2018 Mar.