Sodium Polystyrene Sulfonate

(rINNM)

💊 Chemical information

Natrii polystyrenesulfonas; Natrii Polystyrensulfonas; Natrio polistirensulfonatas; Natriumpolystyreenisulfonaatti; Natriumpolystyrensulfonat; Natrium-polystyrensulfonát; Poliestirenosulfonato sódico; Polystyrène sulfonate sodique; Sodium Polystyrene Sulphonate.
CAS — 9003-59-2; 9080-79-9; 25704-18-1.
ATC — V03AE01.
ATC Vet — QV03AE01.

Pharmacopoeias.

In Eur., Jpn, and US.

Ph. Eur. 6.2

(Sodium Polystyrene Sulphonate). An almost white to light brown powder. It contains 9.4 to 11.0% of sodium, calculated with reference to the dried substance. Each g exchanges 2.8 mmol to 3.4 mmol of potassium, calculated with reference to the dried substance. Practically insoluble in water, in alcohol, and in dichloromethane. Store in airtight containers.

USP 31

(Sodium Polystyrene Sulfonate). A golden brown, fine, odourless powder containing not more than 10% of water. The sodium content is not less than 9.4% and not more than 11.5%, calculated on the anhydrous basis. Each g exchanges not less than 110 mg and not more than 135 mg of potassium, calculated on the anhydrous basis. Insoluble in water.

💊 Adverse Effects

Anorexia, nausea, vomiting, constipation, and occasionally diarrhoea may develop during treatment with sodium polystyrene sulfonate. Constipation may be severe; large doses in elderly patients and in children may result in faecal impaction and gastrointestinal concretions have occurred after oral use in neonates. If necessary a mild laxative may be used to prevent or treat constipation (but see Precautions, below, for laxatives that should be avoided). Serious potassium deficiency can occur with sodium polystyrene sulfonate and signs of severe hypokalaemia may include irritability, confusion, ECG abnormalities, cardiac arrhythmias, and severe muscle weakness. Like other cation-exchange resins, sodium polystyrene sulfonate is not totally selective and its use may result in other electrolyte disturbances such as hypocalcaemia. Significant sodium retention may also occur, especially in patients with renal impairment, and may lead to heart failure.

Effects on the gastrointestinal tract.

Colonic necrosis, including some fatalities, has been reported1-3 after use of enemas containing sodium polystyrene sulfonate in sorbitol. Studies in animals1 suggested that the use of sorbitol was a contributory factor, although failure to irrigate the colon adequately, as recommended by the manufacturer, was also suggested4,5 as a possible cause. Both colonic6 and upper gastrointestinal necrosis7 have also been reported after oral or nasogastric sodium polystyrene sulfonate with sorbitol, and there has also been a report8 of colonic necrosis with oral sodium polystyrene sulfonate alone.
1. Lillemoe KD, et al. Intestinal necrosis due to sodium polystyrene (Kayexalate) in sorbitol enemas: clinical and experimental support for the hypothesis. Surgery 1987; 101: 267–72
2. Wootton FT, et al. Colonic necrosis with Kayexalate-sorbitol enemas after renal transplantation. Ann Intern Med 1989; 111: 947–9
3. Rogers FB, Li SC. Acute colonic necrosis associated with sodium polystyrene sulfonate (Kayexalate) enemas in a critically ill patient: case report and review of the literature. J Trauma 2001; 51: 395–7
4. Burnett RJ. Sodium polystyrene-sorbitol enemas. Ann Intern Med 1990; 112: 311–12
5. Shepard KV. Cleansing enemas after sodium polystyrene sulfonate enemas. Ann Intern Med 1990; 112: 711
6. Rashid A, Hamilton SR. Necrosis of the gastrointestinal tract in uremic patients as a result of sodium polystyrene sulfonate (Kayexalate) in sorbitol: an underrecognized condition. Am J Surg Pathol 1997; 21: 60–9
7. Abraham SC, et al. Upper gastrointestinal tract injury in patients receiving kayexalate (sodium polystyrene sulfonate) in sorbitol: clinical, endoscopic, and histopathologic findings. Am J Surg Pathol 2001; 25: 637–44
8. Cheng ES, et al. Colonic necrosis and perforation following oral sodium polystyrene sulfonate (Resonium A /Kayexelate ) in a burn patient. Burns 2002; 28: 189–90.

Effects on the lungs.

Particles of sodium polystyrene sulfonate were found at autopsy in the lungs of 3 patients who had taken the resin orally and were associated with acute bronchitis and bronchopneumonia in 2 and with early bronchitis in the third.1 It was suggested that, where possible, it may be preferable to give sodium polystyrene sulfonate rectally, but if it has to be given orally the patient should be positioned carefully to avoid aspiration.
1. Haupt HM, Hutchins GM. Sodium polystyrene sulfonate pneumonitis. Arch Intern Med 1982; 142: 379–81.

💊 Precautions

Sodium polystyrene sulfonate should not be given orally to neonates, and is contra-indicated by any route in neonates with reduced gut motility or in any patient with obstructive bowel disease. Care is also needed with rectal use in neonates and children in order to avoid impaction of the resin. Treatment should be discontinued if clinically significant constipation develops. Although sorbitol has been recommended for the prophylaxis and treatment of constipation, there have been reports of colonic necrosis in patients receiving this combination (see Effects on the Gastrointestinal Tract, above) and licensed product information advises against the use of sorbitol with polystyrene sulfonates. Magnesium-containing laxatives are also contra-indicated (see Interactions, below). Patients receiving sodium polystyrene sulfonate should be monitored for electrolyte disturbances, especially hypokalaemia. Since serum concentrations may not always reflect intracellular potassium deficiency, symptoms of hypokalaemia should also be watched for and the decision to stop treatment assessed individually. Use of sodium polystyrene sulfonate can result in sodium overloading and it should be used cautiously in patients with renal failure or conditions requiring a restricted sodium intake, such as heart failure and severe hypertension; calcium polystyrene sulfonate may be preferred in these patients. The possible effects of sodium polystyrene sulfonate on serum electrolytes should be considered when interpreting diagnostic measurements. After use of sodium polystyrene sulfonate retention enemas, the colon should be irrigated to ensure removal of the resin.

💊 Interactions

Sodium polystyrene sulfonate is not totally selective for potassium and may also bind other cations. When given orally with cation-donating antacids and laxatives such as magnesium hydroxide, aluminium hydroxide, or calcium carbonate, competition for binding sites may reduce the potassium-lowering effect of the resin. In addition, particularly in patients with renal impairment, metabolic alkalosis may develop due to binding of the cation by the resin; this prevents neutralisation of bicarbonate ions in the small intestine. Seizures have been reported due to metabolic alkalosis in a patient given magnesium hydroxide with sodium polystyrene sulfonate and use of magnesium-containing laxatives should therefore be avoided. Ion-exchange resins may also bind other drugs, reducing their absorption. Drugs that have been affected include levothyroxine and lithium salts. Hypokalaemia may exacerbate the adverse effects of digoxin and sodium polystyrene sulfonate should be used with caution in patients receiving cardiac glycosides.

💊 Uses and Administration

Sodium polystyrene sulfonate, the sodium salt of sulfonated styrene copolymer with divinylbenzene, is a cation-exchange resin that exchanges sodium ions for potassium ions and other cations in the gastrointestinal tract when given orally or rectally. The exchanged resin is then excreted in the faeces. Each gram of resin exchanges about 3 mmol of potassium in vitro, and about 1 mmol in vivo. Sodium polystyrene sulfonate is used to enhance potassium excretion in the treatment of hyperkalaemia, including that associated with anuria or severe oliguria (caution is required due to the sodium content). An effect may not be evident for several hours or longer, and in severe hyperkalaemia, where a rapid effect is required, other measures must also be considered. Serum-electrolyte concentrations should be monitored throughout treatment and doses given according to response. The usual oral dose is 15 g up to four times daily as a suspension in water or syrup or as a sweetened paste. It should not be given in fruit juices that have a high potassium content. A suggested oral dose for children is 1 g/kg daily in divided doses for acute hyperkalaemia, reduced to a maintenance dose of 500 mg/kg daily; the oral route is not recommended for neonates. When oral use is difficult, sodium polystyrene sulfonate may be given rectally as an enema. The usual daily dose is 30 g given as a suspension in 100 mL of 2% methylcellulose ‘450’ and 100 mL of water and retained, if possible, for at least 9 hours; higher doses, shorter retention times, and alternative vehicles have also been used. After retention of the enema the colon should be irrigated to remove the resin. Initial therapy may involve both oral and rectal routes. Children and neonates may be given rectal doses similar to the oral doses suggested for children; particular care is needed with rectal use in children as excessive dosage or inadequate dilution could result in impaction of resin. Other polystyrene sulfonate resins include calcium polystyrene sulfonate, which is used similarly to the sodium resin and potassium polystyrene sulfonate, which has been used in the treatment of hypercalciuria. Aluminium polystyrene sulfonate, ammonium polystyrene sulfonate, and magnesium polystyrene sulfonate have all occasionally been used.

💊 Preparations

USP 31: Sodium Polystyrene Sulfonate Suspension.

Proprietary Preparations

Austral.: Resonium A; Austria: Resonium A; Belg.: Kayexalate; Canad.: K-Exit; Kayexalate; Denm.: Resonium; Fin.: Resonium; Fr.: Kayexalate; Ger.: Elutit-Natrium; Resonium A; Gr.: Kayexalate; Hong Kong: Resonium A; Hung.: Resonium A; Irl.: Resonium A†; Israel: Kayexalate; Ital.: Kayexalate; Malaysia: Resonium A†; Neth.: Resonium A; NZ: Resonium A; Pol.: Resonium A; Port.: Resonium; S.Afr.: Kexelate; Singapore: Resinsodio; Spain: Resinsodio; Swed.: Resonium; Switz.: Resonium A; Thai.: Kayexalate; Resinsodio; Resonium A; UK: Resonium A; USA: Kayexalate; Kionex; SPS; Venez.: Kayexalate. Multi-ingredient: Ger.: Ujostabil†.
Published December 30, 2018.