From the Research
Ondansetron is the most effective antiemetic for managing ketamine-induced nausea and vomiting, due to its ability to block serotonin 5-HT3 receptors in the chemoreceptor trigger zone and gastrointestinal tract. The typical adult dose is 4-8 mg administered intravenously or orally before ketamine administration, which can be repeated every 8 hours as needed 1. For children, the dose is typically 0.1 mg/kg up to a maximum of 4 mg.
Some key points to consider when using ondansetron for ketamine-induced nausea and vomiting include:
- Prophylactic administration before ketamine is more effective than treating symptoms after they appear 1
- Alternative options include dexamethasone (4-8 mg IV) which can be used in combination with ondansetron for enhanced effect, or metoclopramide (10 mg IV for adults) 2
- Patients should be monitored for potential side effects of ondansetron, which may include headache, constipation, or rarely QT interval prolongation, though these are generally minimal compared to the benefits of preventing nausea and vomiting 3
It's worth noting that while other antiemetics may be effective, ondansetron has been shown to be a highly effective and well-tolerated option, making it a good choice for managing ketamine-induced nausea and vomiting 4, 5. Additionally, the most recent and highest quality study available supports the use of ondansetron as the first-line treatment for nausea and vomiting in the emergency department 1.