Ondansetron (Zofran) has been off patent and its price has dropped to the point that it has supplanted promethazine (Phenergan) and even metoclopramide (Reglan) as the antiemetic of choice. With its low side-effect profile and known efficacy it is now being utilized in hyperemesis gravidarum and in pediatric gastroenteritis. - A cochrane review showed ondansetron to be both safe and effective in the pediatric population. Consider it prior to attempting oral rehydration therapy to increase effectiveness. - Dose: 0.1 mg/kg - you can give the oral dissolvable tablet (ODT) - ages 4-11 you can give 4mg ODT - Above age 11 the dosing is the same as an adult.
Antiemetics for reducing vomiting related to acute gastroenteritis in children and adolescents. Alhashimi D, Al-Hashimi H, Fedorowicz Z. Cochrane Database Syst Rev. 2009 Apr 15;(2):CD005506.