From the Guidelines
Ondansetron is a serotonin 5-HT3 receptor antagonist used to prevent nausea and vomiting caused by chemotherapy, radiation therapy, and surgery. It is available in various forms, including tablets, orally disintegrating tablets, and injections. The usual adult dose for chemotherapy-induced nausea is 8mg taken 30 minutes before treatment begins, with additional doses given 8 hours apart, as recommended by the American Society of Clinical Oncology 1. For post-operative nausea, a single 4mg dose is often administered before anesthesia. Ondansetron works by blocking the action of serotonin, a natural substance that may cause nausea and vomiting, and is particularly effective because it targets specific receptors in both the brain and digestive tract that trigger the vomiting reflex.
- Key characteristics of ondansetron include:
- Effective in preventing acute emesis, but less effective in preventing delayed emesis compared to other 5-HT3 antagonists like palonosetron 1
- Available in various forms, including tablets, orally disintegrating tablets, and injections
- Common side effects include headache, constipation, dizziness, and rarely, heart rhythm changes
- Patients should inform their healthcare provider about other medications they're taking, as ondansetron can interact with certain drugs. The most recent and highest quality study recommends ondansetron as a first-line treatment for preventing nausea and vomiting caused by chemotherapy, with a strong strength of recommendation and high quality of evidence 1.
From the FDA Drug Label
Ondansetron tablets are a 5-HT 3receptor antagonist indicated for the prevention of: nausea and vomiting associated with highly emetogenic cancer chemotherapy, including cisplatin greater than or equal to 50 mg/m 2. ( 1) nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy. ( 1) nausea and vomiting associated with radiotherapy in patients receiving either total body irradiation, single high-dose fraction to the abdomen, or daily fractions to the abdomen. ( 1) postoperative nausea and/or vomiting. ( 1)
- Ondansetron is a 5-HT3 receptor antagonist.
- It is used to prevent nausea and vomiting in various clinical settings, including cancer chemotherapy and radiotherapy, as well as postoperative nausea and/or vomiting 2.
From the Research
Definition and Mechanism of Action
- Ondansetron is a selective 5-HT3 receptor antagonist, which means it works by blocking the action of serotonin at specific receptors in the body 3, 4.
- This mechanism of action makes ondansetron an effective antiemetic agent, used to prevent and treat nausea and vomiting caused by chemotherapy, radiotherapy, and surgery 3, 4, 5.
Therapeutic Uses
- Ondansetron is used as prophylaxis against nausea and vomiting associated with emetogenic chemotherapy, radiotherapy, and anesthesia and surgery 3, 4, 5.
- It is also used to treat nausea and vomiting that has already commenced, including chemotherapy-induced emesis refractory to conventional antiemetic therapy 3, 4.
- In addition to its established indications, ondansetron may be beneficial in novel applications, such as treating nausea and vomiting associated with drug overdosage or poisoning, anti-infective or antidepressant therapies, and certain pain or CNS-related disorders 6.
Efficacy and Safety
- Ondansetron has been shown to be effective in managing chemotherapy-induced nausea and vomiting, with a significant improvement in patient outcomes 5.
- The drug is generally well tolerated, with common adverse events including headache, constipation, and diarrhea 3, 4.
- Ondansetron has a lower incidence of sedation and extrapyramidal reactions compared to conventional antiemetics, making it a preferred treatment option for many patients 6.