For pediatric patients with gastroenteritis and vomiting, treatment with ondansetron is associated with a reduction in return emergency department (ED) visits within 72 hours, according to a study published in Annals of Family Medicine.

The study authors found wide variation in prescription rates for ondansetron during their preliminary research and sought to find a link between an ondansetron prescription and the reduced likelihood of returning to the ED. Researchers conducted a retrospective cohort study of patients aged 6 months to 18 years who presented to a large, urban, tertiary care, pediatric ED and its 11 affiliated urgent care centers from 2012 to 2017. Patients were included if they had an index visit (defined as a patient who had no other ED or urgent care visits in the past 30 days) and were discharged home with a diagnosis of ≥1 of the following: gastroenteritis, vomiting and diarrhea, vomiting alone, gastritis, or dehydration with vomiting.

Several data points were collected, including patient demographics, date and location of visit, type of health insurance, Emergency Severity Index (ESI) level, preexisting medical conditions, interventions at the hospital, prescriptions ordered for home, and 72-hour and 1-week return visits associated with their diagnoses.

Continue Reading

The primary outcome was the rate of return visits for patients diagnosed with gastroenteritis within 72 hours. In the secondary analysis, the rate of how many returning patients were found to have 1 of 5 alternate diagnoses: appendicitis, intussusception, intracranial mass, meningitis, and diabetic ketoacidosis on return visits within 7 days was measured.

Out of 82,139 patients included in the study, 11,004 (13.4%) were prescribed ondansetron. Of the patients, the majority (84.9%) were of Hispanic descent, 7.7% were Black, and 6% were of other or unknown race. A total of 69.7% were primarily insured by Medicaid. Older patients were more likely to receive an ondansetron prescription; Medicaid-insured, Black, and non-Hispanic patients were less likely to receive an ondansetron prescription.

More than half of the index visits (58.9%) took place in the ED; 22.3% of patients were treated by a pediatric emergency medicine-trained physician. Ondansetron was administered during 55.1% of patient visits, an intravenous fluid bolus was given to 7.9% of patients, and a radiologic study was ordered for 13.5%.

Less than 5% of patients had a return visit within 72 hours. Patients who were prescribed ondansetron were less likely to return, as were patients who were treated by a pediatric emergency medicine-trained physician (vs a pediatrician). Black patients were less likely to have a return visit within 72 hours, but Hispanic patients, those who received an intravenous fluid bolus, those who had a radiologic study performed, those who were administered ondansetron during their visit, and those who were treated in the ED (vs an urgent care) were more likely to have a return visit within 72 hours.

For patients who were specifically diagnosed with gastroenteritis (55.6%), receiving an ondansetron prescription was linked to decreased odds of returning within 72 hours. Three patients in this subgroup were diagnosed with appendicitis on their return visit following receipt of ondansetron compared with 23 patients who did not receive a prescription for ondansetron.

Out of all patients who were prescribed ondansetron, 6 were diagnosed with appendicitis during their return visit (0.05%). None of the 16 patients who were diagnosed with intussusception within 72 hours were prescribed ondansetron; neither were the 2 patients who were diagnosed with meningitis during their return visit. No patients were diagnosed with an intracranial mass or diabetic ketoacidosis during their return visit.

The authors found that receiving an ondansetron prescription was associated with reduced 72-hour return visits for children with vomiting or gastroenteritis and was not associated with masking alternate diagnoses. “Despite a relatively large number needed to treat, we believe this is clinically significant because of the large proportion of patients who are treated in the ED for these complaints,” they concluded


Benary D, Lozano JM, Higley R, Lowe D. Ondansetron prescription is associated with reduced return visits to the pediatric emergency department for children with gastroenteritis [published online May 26, 2020]. Ann Emerg Med. doi:10.1016/j.annemergmed.2020.04.012