What education should be given to a patient about Zofran (ondansetron) prescribed and administered in a clinical setting?

Patient Education for Zofran (Ondansetron)

Zofran is a medication that prevents nausea and vomiting by blocking serotonin receptors in your gut and brain, and you should understand how to take it properly, what side effects to watch for, and when to seek immediate medical attention. 1, 2

What Zofran Does and How to Take It

• Zofran works by blocking serotonin (5-HT3) receptors in your gastrointestinal tract and in the brain's chemoreceptor trigger zone, which prevents the signals that cause nausea and vomiting 3
• The medication reaches peak levels in your blood about 1-2 hours after taking it by mouth, so it should be taken at least 30 minutes before chemotherapy or radiation treatment for best results 4, 3
• You may receive Zofran as an 8 mg tablet, oral dissolving tablet, oral film, or as an IV injection depending on your clinical situation 5, 1
• If you received IV Zofran in the hospital, you may be prescribed oral tablets to continue at home—both forms work effectively 5, 1

Critical Heart Safety Warning

• Zofran can cause serious heart rhythm problems called QT prolongation, which may lead to a potentially fatal irregular heartbeat called Torsade de Pointes 1, 2, 6
• Seek immediate medical attention if you experience a change in your heart rate, feel lightheaded, or faint 1, 2
• You are at higher risk for heart problems if you have a personal or family history of abnormal heart rhythms (especially long QT syndrome), take diuretics (water pills), or have low potassium or magnesium levels 2
• The maximum safe single IV dose is 16 mg, and the maximum daily dose by any route is 32 mg per 24 hours 5, 6

Serious Allergic Reactions

• Immediately report fever, chills, rash, hives, difficulty breathing, or any signs of an allergic reaction to your healthcare provider, as Zofran can rarely cause severe reactions including anaphylaxis 1, 2
• Stop taking the medication and seek emergency care if you develop severe breathing problems or swelling of your face, lips, or throat 1, 2

Important Drug Interactions

• Never take Zofran with apomorphine (used for Parkinson's disease), as this combination can cause a dangerous drop in blood pressure and loss of consciousness 1, 2
• Tell your healthcare provider about all medications you take, especially antidepressants or migraine medications, as combining these with Zofran can cause serotonin syndrome 1, 2
• Seek immediate medical attention if you develop confusion, agitation, rapid heart rate, high fever, muscle stiffness, or tremors—these may be signs of serotonin syndrome 1, 2

Bowel Obstruction Warning

• If you've had abdominal surgery or are receiving chemotherapy, Zofran may mask the warning signs of a bowel obstruction 1, 2
• Immediately report severe abdominal pain, severe constipation, bloating, or inability to pass gas or stool to your healthcare provider 1, 2

Common Side Effects and Management

• Constipation is the most common side effect and worsens with higher doses and longer use 7
• Drink plenty of fluids and consider using stool softeners if constipation develops 7
• Headache is another common side effect but rarely requires stopping the medication 3

Chest Pain Warning

• Zofran may rarely cause myocardial ischemia (reduced blood flow to the heart) 1
• Seek immediate medical help if you develop sudden chest pain or chest tightness 1

How Long to Take Zofran

• Take Zofran only on days when you need antiemetic therapy—it should not be taken indefinitely 7
• For chemotherapy: typically 1-3 days after treatment depending on your regimen 8
• For radiation therapy: on treatment days plus 1-2 days after each session 8, 7
• If nausea persists beyond the expected timeframe, contact your healthcare provider rather than continuing Zofran indefinitely, as this may indicate another problem 7

When to Contact Your Healthcare Provider

• If nausea and vomiting are not controlled despite taking Zofran as prescribed 8
• If you develop any of the serious symptoms mentioned above (heart rhythm changes, allergic reactions, chest pain, or signs of bowel obstruction) 1, 2
• If you experience persistent constipation that doesn't improve with fluids and stool softeners 7
• Before taking any new medications, including over-the-counter drugs and supplements 1, 2

Storage and Handling

• Store Zofran tablets at room temperature between 68°F to 77°F (20°C to 25°C) 1
• Keep the medication in its original container and out of reach of children 1