In this session, we will be discussing the consumer medication information for ondansetron, trade name ZofranTM.

What it’s for & How to take

Ondansetron works to help block natural chemicals in your brain that may increase nausea and vomiting.

Ondansetron is used, by itself or along with other medications, to treat nausea and vomiting caused by cancer chemotherapy and radiation therapy. This medication is also used to help nausea and vomit you may have after surgery.

This medication is sometimes used to treat nausea and vomiting for reasons that are not listed here. If you are taking ondansetron to treat nausea and vomiting caused by some reason not listed here, talk with your pharmacist or doctor about it.

This medication comes as an oral tablet that you swallow or a tablet that you dissolve in your mouth. The tablet that dissolves in your mouth is used when you are unable to swallow medications because they may make you vomit.

Your first dose of ondansetron is usually taken 30-60 minutes before the start of chemotherapy, radiation treatment, or surgery. Additional doses are sometimes prescribed to be taken 1-3 times a day during or after chemotherapy or radiation treatment.

If you are taking the tablet that dissolves in your mouth, remove the tablet from the package just before you take your dose. Do not push the tablet through the foil backing of the blister because it may crush the tablet. Peel back the foil backing and place the tablet on your tongue. The tablet will dissolve in a few seconds and can be swallowed with saliva.

If you are taking this medication on a schedule and you forget to take a dose, take it as soon as you remember. If it is near the time of your next dose, skip it and continue with your normal dose time. Do not take a double dose to make up the missed dose.

Your dose is based on your condition and response to treatment. Do not take more than the doctor has ordered for you. If your condition does not improve or gets worse, call your doctor.

Warnings & Cautions

  • Tell your doctor if you have ever been told you have any heart rhythm problems. Rarely, ondansetron may cause your heart to beat fast and unsteady. If you feel any severe dizziness or feel like your heart is racing or beating too fast, get medical help right away.
  • This medication may make you dizzy, drowsy, or blur your vision. Do not drive or do any activity that requires focus and attention until you are sure you can do them safely. Avoid alcoholic beverages while taking ondansetron.
  • Ondansetron orally dissolving tablets may contain phenylalanine. Tell your doctor if you have phenylketonuria.
  • Let your pharmacist or doctor know if you are pregnant or breastfeeding before taking this medication.

Interactions & Side Effects

  • Tell your pharmacist or doctor all your medication allergies so they may determine if ondansetron is safe for you to take.
  • Avoid dangerous drug interactions. Tell your pharmacist or doctor all the other medication you are taking, including over the counter supplements, even if you don’t take them very often.
  • Ask your doctor if this medication is safe to take with your current health conditions. Tell your doctor if you have a history of liver disease, heart disease, any stomach or intestinal problems, or any other medical conditions you have.
  • While taking ondansetron, you may feel some headache, dizziness, drowsiness, sleepiness, constipation or diarrhea. If these or any other unwanted side effects persist, contact your doctor or pharmacist to talk about it with them.
  • Call your doctor right away if you have any significant blurred vision or temporary vision loss, slow heart rate, trouble breathing, anxiety, agitation, shivering, feeling like you might pass out, or urinating less than usual.
  • Call emergency 911 if you have any symptoms of a heart attack such as chest and left arm pain, shortness of breath and sweating or if you have symptoms of a stroke such as weakness on one side of your body, slurred speech, sudden vision changes, and confusion.

If you have any questions about what you have heard, contact your pharmacist or doctor. This session does not include all the potential interactions or side effects that this medication may cause. Ask your pharmacist how your medication should be stored and how you should dispose of it when you are done taking it. Do not share your medication with anyone, ever. Remember, this is not meant to replace your counseling session with your pharmacist. In case of overdose, call your local poison control center at 1-800-222-1222.

Updated 7/20