From the Guidelines
Ondansetron is recommended for children over 2 years old at a dose of 0.15 mg/kg orally, up to a maximum of 8 mg per dose, as it has been shown to be superior to other antiemetic agents with less toxicity 1. When administering ondansetron to children, it is essential to consider their weight, as the dose should be calculated based on weight for children weighing less than 40 kg. For children 40 kg or more, the adult dose of 4-8 mg can be used.
- The medication can be given every 8 hours as needed for nausea and vomiting, with a maximum of 3 doses in 24 hours.
- Ondansetron is available as oral tablets, orally disintegrating tablets (which dissolve on the tongue without water), and oral solution.
- The orally disintegrating tablets are particularly useful for children who have difficulty swallowing pills.
- Ondansetron works by blocking serotonin receptors in the chemoreceptor trigger zone and in the gastrointestinal tract, which helps prevent nausea and vomiting.
- Common side effects include headache and constipation.
- Rare but serious side effects include QT interval prolongation, so caution should be used in children with congenital long QT syndrome or those taking other medications that can prolong the QT interval 1. The combination of a 5-HT3 receptor antagonist, such as ondansetron, with dexamethasone has been shown to be more efficacious than a 5-HT3 receptor antagonist alone in preventing chemotherapy-induced nausea and vomiting in pediatric patients 1.
From the FDA Drug Label
Pediatric Trials Three open-label, single-arm, non-US trials have been performed with 182 pediatric patients aged 4 to 18 years with cancer who were given a variety of cisplatin or non cisplatin regimens. The initial dose of ondansetron tablets injection ranged from 0. 04 to 0.87 mg per kg (total dose of 2. 16 mg to 12 mg) followed by the administration of oral doses of ondansetron tablets ranging from 4 to 24 mg daily for 3 days. In these trials, 58% of the 170 evaluable patients had a complete response (no emetic episodes) on Day 1 In 2 trials the response rates to ondansetron tablets 4 mg three times a day in patients younger than 12 years was similar to ondansetron tablets 8 mg three times daily in patients 12 to 18 years.
The recommended dose of ondansetron PO in children over 2 years old is not explicitly stated, but based on the pediatric trials, 4 mg three times a day can be considered for patients younger than 12 years. However, the exact dosing for children over 2 years old is not directly provided in the label. 2
From the Research
Ondansetron PO in Children >2 Years Old
- The use of ondansetron in children has been studied in various settings, including chemotherapy-induced nausea and vomiting, postoperative nausea and vomiting, and gastroenteritis 3, 4, 5, 6.
- In children receiving chemotherapy, ondansetron has been shown to be effective in preventing nausea and vomiting, with a significant reduction in emetic episodes compared to other antiemetics such as metoclopramide and chlorpromazine 3.
- Oral ondansetron has been found to be effective in controlling chemotherapy-induced nausea and vomiting in children, with a reduction in hospitalization and no significant toxicity encountered 5.
- In children with gastroenteritis, a single dose of oral ondansetron has been shown to reduce vomiting and facilitate oral rehydration, with a significant reduction in the need for intravenous rehydration and hospitalization 6.
- The optimal dose of ondansetron in children is not well established, but studies suggest that doses ranging from 0.1 to 0.15 mg/kg are effective in preventing emesis in children undergoing surgery or receiving chemotherapy 3, 4.
- Ondansetron is generally well tolerated in children, with mild to moderate adverse events such as headache, constipation, and diarrhea reported in some studies 3, 4, 5, 6.