Ondansetron, marketed under the brand name Emadon, is a medication primarily used to prevent nausea and vomiting associated with various medical treatments, including chemotherapy, radiation therapy, and postoperative recovery. It belongs to a class of drugs known as serotonin 5-HT3 receptor antagonists.
Key Uses
- Chemotherapy-Induced Nausea and Vomiting: Effective in preventing nausea and vomiting during and after chemotherapy, particularly with highly emetogenic agents like cisplatin.
- Radiation Therapy: Used to manage nausea and vomiting resulting from radiation treatment.
- Postoperative Nausea and Vomiting: Helps prevent nausea and vomiting that can occur after surgical procedures.
Mechanism of Action
Ondansetron works by blocking the action of serotonin at the 5-HT3 receptors in the gut and brain. By inhibiting these receptors, it effectively reduces the signals that trigger nausea and vomiting.
Dosage and Administration
- Typical Dosage for Adults:
- For chemotherapy: 24 mg orally 30 minutes before the start of chemotherapy or 8 mg orally twice daily.
- For postoperative use: 16 mg orally one hour before anesthesia.
- Administration Instructions: Ondansetron can be taken as a tablet, orally disintegrating tablet, or liquid solution. It is recommended to take it before the onset of nausea.
Side Effects
Common side effects may include:
- Headache
- Dizziness
- Drowsiness
- Constipation or diarrhea
Serious side effects can include:
- Allergic reactions (e.g., rash, swelling)
- Heart rhythm changes (QT prolongation)
- Severe constipation or abdominal pain
Patients should seek immediate medical attention if they experience severe side effects such as difficulty breathing, swelling of the face or throat, or signs of an allergic reaction.
Precautions
- Contraindications: Should not be used in individuals with a known allergy to ondansetron or similar medications. Caution is advised for those with liver disease or a history of heart rhythm disorders.
- Pregnancy and Breastfeeding: Consult a healthcare provider before use during pregnancy or breastfeeding.
