Assessment of Ondansetron-Associated Hypokalemia in Pediatric Oncology Patients

Abstract

Objectives. Ondansetron is a 5-hydroxytryptamine (5-HT3, serotonin) receptor antagonist used as antiemetic prophylaxis preceding chemotherapy administration. Hypokalemia is a rare complication of ondansetron, which may be underreported due to confounding emesis and chemotherapy-induced tubulopathy. We performed a prospective cohort study to determine if ondansetron caused significant hypokalemia independently as a result of renal potassium wasting. Methods. Twelve patients were recruited, with ten completing the study. Blood and urine samples were collected before and after ondansetron administration in patients admitted for intravenous (IV) hydration and chemotherapy. Dietary histories and IV records were analyzed to calculate sodium and potassium balances. Results. We observed an expected drop in urine osmolality, an increase in urine sodium, but no statistically significant change in sodium or potassium balance before and after ondansetron. Conclusion. Ondansetron does not cause significant potassium wasting in appropriately hydrated and nutritionally replete patients. Careful monitoring of serum potassium is recommended in patients with chronic nutritional or volume status deficiencies receiving this medication.

Severe Ondansetron-associated Hypokalemia in a Patient Diagnosed with Aspiration Pneumonia

“…Moreover, in the nephron, especially the distant hinge, Na+-K+ ATPase is adjusted by ondansetron. It causes worsening of renal K dissipation in discarded cells expressing ENaC [ Figure 2 ][ 12 ] by decreasing intracellular sodium levels that increase sodium tubular entry into this section. Matthews et al .…”

“…Ten patients admitted for IV hydration and chemotherapy were assessed by Friedrich et al . [ 12 ] for ondansetron-related hypokalemia in nearby oncology patients. Blood and urine samples were gathered before and after ondansetron administration, and dietary records and IV reports were analyzed to compute sodium and potassium balance.…”

“…They concluded that ondansetron does not result in considerable loss of potassium in hydrated and nourished patients but recommended careful monitoring of serum potassium in patients with nutritional deficiencies or chronic volume deficiencies who receive the drug. [ 12 ]…”