From the Guidelines
For a 9 kg child with vomiting, the recommended ondansetron dose is 0.15 mg/kg, which translates to 1.35 mg, but a commonly used dose is 0.1 mg/kg, resulting in a dose of 0.9 mg. This dose can be administered orally or intravenously. For oral administration, the closest available dosage form is typically a 2 mg orally disintegrating tablet, which can be cut in half to provide approximately 1 mg, or a 4 mg tablet can be cut into quarters to provide approximately 1 mg. For IV administration, use 0.9 mg (0.1 mg/kg) given slowly over 2-5 minutes 1. Ondansetron can be repeated every 8 hours as needed for continued vomiting. Monitor the child for potential side effects including headache, dizziness, or constipation. Ensure adequate hydration is maintained while the child is vomiting. Ondansetron works by blocking serotonin receptors in the brain and gut that trigger vomiting. If vomiting persists despite medication or is accompanied by concerning symptoms such as severe abdominal pain, lethargy, or signs of dehydration, seek immediate medical attention. Some studies suggest that ondansetron can reduce vomiting in children and reduce the need for hospitalization for rehydration, although it may increase stool volume 1. However, the most relevant and recent guideline for the use of ondansetron in children is from the MASCC and ESMO, which recommends a dose of 0.15 mg/kg or 5 mg/m2 for ondansetron 1. Given the potential benefits and risks, the dose of 0.15 mg/kg (1.35 mg for a 9 kg child) is recommended, but 0.1 mg/kg (0.9 mg for a 9 kg child) can be used as an alternative dose. It is essential to follow the recommended dosage and administration guidelines to minimize the risk of adverse effects and ensure the best possible outcome for the child. In clinical practice, the choice of dose may depend on various factors, including the child's medical history, the severity of vomiting, and the presence of other symptoms or conditions. Therefore, it is crucial to consult with a healthcare professional to determine the most appropriate dose and treatment plan for the child.
From the FDA Drug Label
04 to 0.87 mg per kg (total dose of 2. 16 mg to 12 mg) The appropriate dose of ondansetron (Zofran) for a 9 kilogram child experiencing vomiting is 0.36 to 7.83 mg (calculated by multiplying 9 kg by 0.04 to 0.87 mg per kg). Key points:
- The dose range is 0.04 to 0.87 mg per kg.
- The total dose should be between 2.16 mg to 12 mg. 2
From the Research
Ondansetron Dosing for a 9 Kilogram Child
- The appropriate dose of ondansetron for a 9 kilogram child experiencing vomiting can be determined based on the available evidence.
- According to the study 3, the recommended dose of ondansetron is 0.2 mg/kg oral or 0.15 mg/kg parenteral, with a maximum dose of 4 mg.
- For a 9 kilogram child, the calculated dose would be:
- Oral: 0.2 mg/kg x 9 kg = 1.8 mg
- Parenteral: 0.15 mg/kg x 9 kg = 1.35 mg
- Other studies 4, 5, 6, 7 also support the use of ondansetron in children, but do not provide specific dosing recommendations for a 9 kilogram child.
- However, study 6 suggests that doses ranging from 0.13 to 0.26 mg/kg are effective in preventing emesis in children with acute gastroenteritis, without significant differences in efficacy or side effects.
Considerations for Ondansetron Use
- Ondansetron is indicated for use in children who are unable to take oral fluids due to persistent vomiting, post-operative vomiting, chemotherapy-induced vomiting, cyclic vomiting syndrome, and acute mountain sickness 3.
- The use of ondansetron in children has been shown to be effective in reducing the risk of recurrent vomiting, the need for intravenous fluids, and hospital admissions 4, 7.
- Ondansetron is generally well-tolerated in children, with mild to moderate adverse events such as headache, constipation, and diarrhea 5.