What is Zofran?
Zofran (ondansetron) blocks the actions of chemicals in the body that can trigger nausea and vomiting.
Zofran is used to prevent nausea and vomiting that may be caused by surgery or by medicine to treat cancer (chemotherapy or radiation).
Zofran is not for preventing nausea or vomiting that is caused by factors other than cancer treatment or surgery.
You should not use Zofran if you are allergic to ondansetron or to similar medicines such as dolasetron (Anzemet), granisetron (Kytril), or palonosetron (Aloxi). Do not take this medicine if you are also using apomorphine (Apokyn).
Before taking Zofran, tell your doctor if you have liver disease, or a personal or family history of Long QT syndrome.
Zofran orally disintegrating tablets may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).
Serious side effects of ondansetron include blurred vision or temporary vision loss (lasting from only a few minutes to several hours), slow heart rate, trouble breathing, anxiety, agitation, shivering, feeling like you might pass out, and urinating less than usual or not at all. Stop taking Zofran and call your doctor at once if you have any of these side effects. Ondansetron may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
Before taking this medicine
You should not use Zofran if you are also using apomorphine (Apokyn).
To make sure Zofran is safe for you, tell your doctor if you have:
liver disease; or
if you are allergic to medicines similar ondansetron (dolasetron, granisetron, palonosetron).
FDA pregnancy category B. Zofran is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.
It is not known whether ondansetron passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
Zofran should not be given to a child younger than 4 years old.
Ondansetron orally disintegrating tablets may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).
How should I take Zofran?
Take Zofran exactly as prescribed by your doctor. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Zofran can be taken with or without food.
The first dose is usually taken before the start of your surgery, chemotherapy, or radiation treatment. Follow your doctor’s dosing instructions very carefully.
Take the regular tablet with a full glass of water.
To take the orally disintegrating tablet (Zofran ODT):
Keep the tablet in its blister pack until you are ready to take it. Open the package and peel back the foil. Do not push a tablet through the foil or you may damage the tablet.
Use dry hands to remove the tablet and place it in your mouth.
Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing.
Swallow several times as the tablet dissolves.
Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
Store at room temperature away from moisture, heat, and light.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention.
Overdose symptoms may include sudden loss of vision, severe constipation, feeling light-headed, or fainting.
What should I avoid while taking Zofran?
Zofran may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
Zofran side effects
Get emergency medical help if you have any of these signs of an allergic reaction to Zofran: rash, hives; fever, chills, difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
fast or pounding heartbeats;
jaundice (yellowing of the skin or eyes);
blurred vision or temporary vision loss (lasting from only a few minutes to several hours); or
high levels of serotonin in the body – agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting.
Common Zofran side effects may include:
diarrhea or constipation;
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
What other drugs will affect Zofran?
There are many other medicines that can increase your risk of heart rhythm problems if you use them together with Zofran.
Tell your doctor about all medicines you use, and those you start or stop using during your treatment with ondansetron, especially:
an antibiotic – azithromycin, clarithromycin, erythromycin, levofloxacin, moxifloxacin, pentamidine;
cancer medicine – arsenic trioxide, vandetanib;
an antidepressant – citalopram, escitalopram;
anti-malaria medication – chloroquine, halofantrine;
heart rhythm medicine – amiodarone, disopyramide, dofetilide, dronedarone, flecainide, ibutilide, quinidine, sotalol; or
medicine to treat a psychiatric disorder – chlorpromazine, haloperidol, pimozide, thioridazine.
This list is not complete. Other drugs may interact with ondansetron, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.