Dosing and uses of SPS, Kayexalate (sodium polystyrene sulfonate)
Adult dosage forms and strengths
powder for oral suspension
- 454g
oral suspension
- 15g/60mL
rectal suspension
- 15g/60mL
Hyperkalemia
PO: 15 g once daily or q6-12hr
Rectal: 30-50 g q6hr
Administration
PO: Powdered resin as suspension in water or syrup; for each 1 g of powdered resin, add 3-4 mL of water/syrup; do not refrigerate
Rectal: Powdered resin in 100-200 mL of aqueous vehicle (eg, 25% sorbitol, 10% dextrose, 1% methylcellulose or water), warmed to body temperature; administer cleansing enema first, and retain enema in colon for more than 45 mins if possible
Position patient carefully when administering to avoid aspiration
Lithium Overdose (Off-label)
30 g in sorbitol q4hr; monitor for hypokalemia
Pediatric dosage forms and strengths
powder for oral suspension
- 454g
oral suspension
- 15g/60mL
rectal suspension
- 15g/60mL
Hyperkalemia
PO: 1 g/kg q6hr PRN; alternatively, use exchange ratio of 1 mEq K+ to 1 g of resin for lower dose (oral use not recommended in patients < 1 month old)
Rectal: 1 g/kg q2-6hr PRN; alternatively, use exchange ratio of 1 mEq K+ to 1 g of resin for lower dose
SPS, Kayexalate (sodium polystyrene sulfonate) adverse (side) effects
1-10%
GI disturbance
Constipation
Hypokalemia
Hypocalcemia
Hypomagnesemia
Sodium retention
Nausea
Vomiting
Frequency not defined
GI concretions (bezoars) after oral use
GI tract ulceration or necrosis, which could lead to perforation
Fecal impaction after rectal administration (especially in children)
Acute bronchitis or bronchopneumonia associated with inhalation of polystyrene particles (rare)
Warnings
Contraindications
Hypersensitivity to polystyrene sulfonate resins
Hypokalemia
Obstructive bowel disease
Neonates: Reduced gut motility (postoperative or drug-induced), oral administration
Cautions
Congestive heart failure, severe hypertension, marked edema (due to sodium content; 1 g contains 100 mg of sodium, 1/3 of which is delivered to body)
Best when used in non-life-threatening hyperkalemia
Monitor electrolytes
In severe hyperkalemia, consider more immediate treatment modalities (eg, dialysis, IV calcium, bicarbonate, glucose, and insulin)
Products can contain as much as 20 g of sorbitol per 15 g of sodium polystyrene
Do not use in patients who do not have normal bowel function, including postoperative patients who have not had a bowel movement since operation
Do not mix PO dose with banana or orange juice (potassium-rich)
If there is clinically significant constipation, discontinue until normal bowel motion; do not use magnesium-containing laxatives or sorbitoL
Children and neonates: With rectal administration, excessive dosage or inadequate dilution could result in impaction of resin
Premature and low-birth-weight infants: Risk of digestive hemorrhage or colonic necrosis
Risk of colonic necrosis and other serious GI adverse events (eg, bleeding, ischemic colitis, perforation), most frequently with concomitant use of sorbitoL
Concomitant administration of sorbitol is not recommended
Risk factors for GI adverse events include prematurity, history of intestinal disease or surgery, hypovolemia, and renal insufficiency or failure
Pregnancy and lactation
Pregnancy category: C
Lactation: Unknown if excreted; exercise caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of SPS, Kayexalate (sodium polystyrene sulfonate)
Mechanism of action
Cation exchange resin, sodium ions partially released from polystyrene and replaced by potassium
Absorption
Bioavailability: Nonabsorbable ion-exchange resin
Onset: 2-24 hr
Duration: 4-6 hr
Elimination
Excretion: Feces
