Selection of gastrointestinal cation exchange in hyperkalemia status, case report

Background Gastrointestinal cation exchangers (patiromer, sodium polystyrene sulfonate, and sodium zirconium cyclosilicate) play a critical and evolving role in the treatment of hyperkalemia. Clinicians must tailor their choice to the clinical context, considering the urgency of hyperkalemia, underlying renal failure, or concurrent heart failure medications. Sodium zirconium cyclosilicate (SZC) and patiromer are now clear alternatives to sodium polystyrene sulfonate. The distinct pharmacokinetic profiles of these drugs dictate which agent is optimal for a given situation. Case presentation We present a case of emergency hyperkalemia, dehydration, and high anion gap metabolic acidosis. The patient initially responded rapidly to intravenous fluids, calcium gluconate, and dextrose-insulin infusion. Patiromer clearly failed to maintain normokalemia due to an overlooked history of total colectomy. Switching to SZC produced prompt improvement. Conclusion A gastrointestinal cation exchanger is an essential tool in managing hyperkalemic emergencies. Avoid patiromer in patients with colonic surgeries or chronic constipation. For emergencies, either SZC or patiromer can be used; however, prioritize SZC when a rapid onset (1 hour vs 7 hours) or broader site of action is required.