Kayexalate Pediatric Dose — Hyperkalemia Management
Kayexalate (sodium polystyrene sulfonate) is a cation-exchange resin that binds potassium in the gastrointestinal tract in exchange for sodium, facilitating fecal potassium excretion. It is used in pediatric patients for the management of hyperkalemia across a range of clinical settings, including toxicology, renal failure, and critical illness. Onset of action is relatively slow compared with other potassium-lowering interventions, positioning it as an adjunctive rather than emergent therapy.
Pediatric Dosing
| Route | Dose |
|---|---|
| Oral (PO) | 1 g/kg per dose |
| Rectal (PR) | 1.5–2 g/kg per dose, mixed with 20% sorbitol |
For a 10 kg child: PO dose = 10 × 1 g/kg = 10 g; PR dose = 10 × 1.5–2 g/kg = 15–20 g mixed with 20% sorbitol. Consult institutional protocol regarding maximum single dose, dosing frequency, and preparation specifics.
Indications and Clinical Context
Kayexalate is indicated for the treatment of hyperkalemia in pediatric patients, including scenarios encountered in toxicology (e.g., digoxin or other potassium-altering toxidrome management), acute kidney injury, and chronic renal insufficiency. Because its potassium-lowering effect develops over hours, it is not appropriate as monotherapy for acute life-threatening hyperkalemia with electrocardiographic changes; temporizing measures such as calcium gluconate, sodium bicarbonate, and insulin/dextrose should be prioritized in emergent presentations.
The rectal route may be preferred when oral administration is not feasible or when faster colonic delivery is desired, and is administered as a retention enema mixed with 20% sorbitol to facilitate retention and bowel motility.
Administration and Monitoring
The oral formulation is typically prepared as a suspension; the rectal dose is mixed with 20% sorbitol and administered as a retention enema, retained for the longest period tolerable to maximize potassium exchange. Serum electrolytes—including potassium, sodium, calcium, and magnesium—should be monitored serially, as sodium loading may occur and hypokalemia or hypomagnesemia can develop with repeated dosing.
- Route: PO (suspension) or PR (retention enema with 20% sorbitol)
- Monitoring: Serial serum potassium, sodium, and renal function
- Caution: Use with care in patients with bowel dysmotility, recent bowel surgery, or risk of intestinal necrosis; sorbitol-containing preparations have been associated with intestinal necrosis, particularly in postoperative patients
- Max dose/frequency: Consult institutional protocol
Disclaimer: This article is an educational reference summarizing standard pediatric dosing values. It is not a substitute for clinical judgment. Always verify doses against institutional protocols, the current edition of authoritative references (e.g., Lexicomp, Harriet Lane Handbook, PALS guidelines), the patient’s accurate weight, and any patient-specific factors (renal/hepatic function, allergies, comedications) before administration.