Calcium Polystyrene Sulfonate Induced Necrotizing Ulcerative Enterocolitis - Not Just an Innocent Bystander

Abstract

Introduction and Aims: Resins are non-absorbable medications that facilitates ion exchange and are commonly used in the treatment of hyperkalemia. Crystal deposition by these resins could result in and aggravate colonic mucosal damage. This rare but serious adverse event is under-recognized and is reportedly associated with life-threatening enterocolitis. We would like to present a case of necrotizing ulcerative enterocolitis in a patient with acute dysentery with concomitant calcium polystyrene sulfonate (CPS) prescription. Case Presentation: An 85-year-old lady presented to us with generalized abdominal pain and bloody diarrhea for one week. She was febrile, dehydrated and lethargic. Her abdomen was soft with non-specific generalized mild tenderness. Other clinical examination was unremarkable. Laboratory indices revealed raised inflammatory markers with acute on chronic kidney disease (CKD). Relevant findings include hyperkalemia, metabolic acidosis and tall-tented T waves on her electrocardiographic (ECG) recordings. A working diagnosis of acute dysentery complicated by acute on CKD was made and urgent resuscitative measures begun. While waiting for hemodialysis, she was started on antibiotics, intravenous fluids, oral CPS powder and a cocktail regime of 10% calcium gluconate, insulin and 50% dextrose for hyperkalemia reversal and cardioprotective measures. Despite this, her symptoms worsened with massive bouts of hematochezia requiring blood transfusion three days later. An urgent ileocolonoscopy revealed extensive pancolonic with ileal ulceration. The possibility of ischemic colitis on top of the infectious colitis was considered. Biopsies taken was consistent with CPS-induced necrotizing ulcerative enterocolitis. Her cultures and infective workup were negative. Despite our efforts, she succumbed a week later from multiple contributing issues. Discussion and Conclusion: This case highlights the negative prospect of prescribing CPS to patients with any forms of colitis as it could further worsen the underlying pathology. One needs to be mindful of the adverse event and consider a higher threshold for prescribing it in certain cases.