Ondansetron

What is the most important information I should know about ondansetron?

Do not use this medication if you are allergic to ondansetron or to similar medicines such as dolasetron (Anzemet), granisetron (Kytril), or palonosetron (Aloxi).

Before taking ondansetron, tell your doctor if you have liver disease, or a personal or family history of Long QT syndrome.

Ondansetron orally disintegrating tablets may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).

The serious side effects of this medication include blurred vision or temporary blindness, slow heart rate, trouble breathing, anxiety, agitation, shivering, feeling light-headed, or fainting, and urinating less than usual or not at all. Stop taking ondansetron and call your doctor at once if you have any of these side effects.

Ondansetron can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

What is ondansetron?

Ondansetron blocks the actions of chemicals in the body that can trigger nausea and vomiting.

Ondansetron is used to prevent nausea and vomiting that may be caused by surgery or by medicine to treat cancer (chemotherapy or radiation).

Ondansetron may also be used for other purposes not listed in this medication guide.

What should I discuss with my health care provider before taking ondansetron?

Do not use this medication if you are allergic to ondansetron, to similar medicines such as dolasetron (Anzemet), granisetron (Kytril), or palonosetron (Aloxi).

Before taking ondansetron, tell your doctor if you are allergic to any drugs, or if you have:

• liver disease;
• a history of allergic reaction to any medicine; or
• a personal or family history of Long QT syndrome.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take ondansetron.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Ondansetron can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Ondansetron orally disintegrating tablets may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).

How should I take ondansetron?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Ondansetron can be taken with or without food.

Take the ondansetron regular tablet with a full glass of water.

To take ondansetron orally disintegrating tablet (Zofran ODT):

• Keep the tablet in its blister pack until you are ready to take the medicine. Open the package and peel back the foil from the tablet blister. Do not push a tablet through the foil or you may damage the tablet.
• Using dry hands, remove the tablet and place it in your mouth. It will begin to dissolve right away.
• Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing.
• Swallow several times as the tablet dissolves. If desired, you may drink liquid to help swallow the dissolved tablet.

Measure the liquid form of ondansetron with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

Store ondansetron at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have received too much of this medicine.

Overdose symptoms may include sudden loss of vision, severe constipation, feeling light-headed, or fainting.

What should I avoid while taking ondansetron?

Ondansetron can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

What are the possible side effects of ondansetron?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

• blurred vision or temporary blindness;
• fever;
• slow heart rate, trouble breathing;
• anxiety, agitation, shivering;
• feeling light-headed, fainting; or
• urinating less than usual or not at all.

Less serious side effects may include:

• diarrhea or constipation;
• weakness or tired feeling;
• headache;
• dizziness or drowsiness;

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

What other drugs will affect ondansetron?

Before receiving ondansetron, tell your doctor if you are using any of the following drugs:

• phenytoin (Dilantin), phenobarbital (Luminal);
• carbamazepine (Carbatrol, Tegretol);
• tramadol (Ultram); or
• rifampin (Rifadin, Rimactane, Rifater).

This list is not complete and there may be other drugs that can interact with ondansetron. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about ondansetron.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2003 Cerner Multum, Inc. Version: 6.06. Revision date: 01/09/2008.