Do NOT use Zofran if:

• you are allergic to any ingredient in Zofran
• you are taking apomorphine.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Zofran. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have had an allergic reaction to another serotonin 5-HT₃ receptor blocker (eg, dolasetron, granisetron)
• if you have liver problems or a certain type of irregular heartbeat (QT prolongation, long QT syndrome).

Some medicines may interact with Zofran. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Apomorphine because the risk of its side effects may be increased by Zofran
• Antineoplastic agents (eg, cyclophosphamide) because their effectiveness may be decreased by Zofran.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Zofran may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Zofran may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Zofran with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Zofran should be used with extreme caution in children younger 4 months; safety and effectiveness in these children have not been confirmed. Certain strengths of Zofran are not recommended in children. If you have questions about using Zofran in children, contact your doctor or pharmacist.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Zofran while you are pregnant. It is not known if Zofran is found in breast milk. If you are or will be breast-feeding while you use Zofran, check with your doctor. Discuss any possible risks to your baby.

All medicines may cause side effects, but many people have no, or minor, side effects.

Check with your doctor if any of these most common side effects persist or become bothersome:

Constipation; diarrhea; dizziness; drowsiness; headache; tiredness.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, throat, or tongue; wheezing; unusual hoarseness); chest or jaw pain; fainting; fast, slow, or irregular heartbeat; fever; numbness of an arm or leg, or sudden severe headache or vomiting; seizures; severe or persistent dizziness; skin tingling or numbness; stomach pain; trouble urinating; uncontrolled muscle movements; vision changes or loss.

 This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.