Drugs for nausea. Zofran (ondansetron) is a mainstay for helping pediatric oncology patients with nausea and vomiting (there are other members of this class like kytril). A combination of Benadryl (diphenhydramine) and Reglan (metoclopramide) is also used. Lastly Ativan (lorazepam) is also quite effective. Others used are emend, scopolamine (>10 yo), and Marinol (for teens).
Age and severity. Zofran for age greater than 4, Compazine or Phenergan (promethazine) for age 2 or older, and tigan can be used in all age (no age limit). So, depending on the severity of symptoms, your doc can select from these choices. Zofran can only be given IV or orally. The others can be given rectally as a suppository as well. If you have more concerns, consult your doc. Good luck.