Zofran, known generically as ondansetron, is a widely used medication in Australia to prevent and treat nausea and vomiting caused by various medical treatments. It is particularly effective for patients undergoing chemotherapy, radiotherapy, or surgery, as well as for other causes of severe nausea.
What Is Zofran Used For?
Zofran is primarily prescribed to manage:
- Chemotherapy-induced nausea and vomiting (CINV)
- Radiotherapy-induced nausea and vomiting
- Postoperative nausea and vomiting (PONV)
- Other nausea and vomiting conditions as determined by a healthcare professional
How Does Zofran Work?
Zofran works by blocking serotonin (5-HT3) receptors in the brain and gastrointestinal tract, which play a key role in triggering the vomiting reflex. By inhibiting these receptors, ondansetron effectively reduces nausea and vomiting symptoms.
Available Forms in Australia
Zofran is available in several formulations to suit different patient needs:
- Tablets: 4 mg and 8 mg oral tablets
- Orally Disintegrating Tablets (Zydis wafers): Dissolve quickly on the tongue without water, ideal for patients with difficulty swallowing or severe nausea
- Syrup: Liquid form suitable for children or adults who prefer not to take tablets
- Injection: Intravenous or intramuscular use, mostly in hospital settings
Dosage Guidelines for Adults
Dosing depends on the condition being treated and severity of symptoms:
- Chemotherapy-induced nausea:
- For highly emetogenic chemotherapy, a single 24 mg dose is given 30 minutes before treatment.
- For moderately emetogenic chemotherapy, 8 mg is taken 30 minutes before treatment, followed by 8 mg doses 8 hours later and twice daily for 1–2 days after chemotherapy.
- Radiotherapy-induced nausea:
- 8 mg orally 1–2 hours before treatment, repeated every 12 hours during therapy.
- Postoperative nausea:
- A single 4 mg oral dose 1 hour before anesthesia or 16 mg orally 1 hour before anesthesia in some cases.
- Treatment of established nausea and vomiting:
- 4 mg every 6 to 8 hours as needed, not exceeding 20 mg per day.
Special Considerations
- Elderly patients: May require dose adjustments due to slower drug clearance.
- Liver impairment: Dosage should be reduced in severe hepatic dysfunction.
- Pregnancy: Used cautiously, especially in the first trimester, under medical supervision.
- Children: Dosage is weight or body surface area-based and generally not recommended under 4 years without specialist advice.
Side Effects to Be Aware Of
Common side effects include headache, constipation, dizziness, and fatigue. Rare but serious effects include allergic reactions and heart rhythm disturbances (QT prolongation). Always consult your healthcare provider if you experience unusual symptoms.
Prescription and Availability
Zofran is a prescription-only medicine in Australia and can be obtained from pharmacies with a valid prescription. It is listed on the Pharmaceutical Benefits Scheme (PBS), making it accessible at subsidised costs for eligible patients.
Zofran (ondansetron) is a trusted and effective medication for managing nausea and vomiting in Australia, especially related to cancer treatments and surgery. Its various formulations and dosing options allow tailored treatment to individual needs. Always use Zofran under the guidance of a healthcare professional to ensure safety and effectiveness.