From the Guidelines
For a child weighing 13 kg, the recommended Zofran (ondansetron) dose is 2 mg every 8 hours as needed for nausea and vomiting, based on the standard pediatric dosing of 0.15 mg/kg per dose, as established in clinical practice 1. This dose calculation is derived from the standard pediatric dosing guideline, which recommends 0.15 mg/kg per dose, resulting in 1.95 mg for a 13 kg child, rounded to 2 mg for practical administration.
Administration and Formulation
Zofran can be given orally as a tablet, orally disintegrating tablet (ODT), or liquid formulation. The ODT form dissolves on the tongue without water, which may be easier for a child experiencing nausea.
Alternative Administration
For severe nausea or if the child cannot take oral medication, the same dose can be given intravenously by a healthcare provider.
Dosage Limitation
Do not exceed 3 doses in 24 hours unless directed by a healthcare provider.
Mechanism of Action
Zofran works by blocking serotonin receptors in the brain and gut that trigger nausea and vomiting.
Potential Side Effects
Side effects may include headache, mild dizziness, or constipation.
Monitoring and Follow-up
Contact a doctor if the child experiences severe side effects or if vomiting persists despite medication. The most recent and relevant guideline for pediatric dosing of ondansetron is from 1, which provides the basis for this recommendation, prioritizing the child's morbidity, mortality, and quality of life.
From the Research
Ondansetron Dosing for Children
- The recommended dose of Ondansetron for children is not explicitly stated in the provided studies, but a dose range can be inferred from the available data.
- A study published in 2010 2 analyzed data from a prospective clinical trial and found that the dose of ondansetron ranged between 0.13 and 0.26 mg/kg, with no significant association between the dose and the outcomes of number of vomiting episodes, volume of fluids consumed, increase in body weight, or number of diarrhea episodes/hour.
- For a child weighing 13 kilograms, the dose would be approximately 1.69-3.38 mg (0.13 mg/kg x 13 kg = 1.69 mg and 0.26 mg/kg x 13 kg = 3.38 mg).
- Another study published in 2020 3 found that a single dose of ondansetron was effective in reducing vomiting in children and adolescents with acute gastroenteritis, but the optimal dose was not specified.
Considerations for Ondansetron Use in Children
- Ondansetron is generally well tolerated in children, but adverse effects such as headache, diarrhea, and constipation can occur 4, 5.
- The half-life of ondansetron is approximately 3.5 hours, slightly shorter in children 6.
- Ondansetron is eliminated almost entirely by hepatic metabolism, with less than 5% of an intravenously administered dose recovered intact in urine 6.