ondansetron (oral)

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

You should not use this medication if you are allergic to ondansetron or to similar medicines such as dolasetron (Anzemet), granisetron (Kytril), or palonosetron (Aloxi). Do not take ondansetron if you are also using apomorphine (Apokyn).

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 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 ondansetron 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.

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 be used for purposes not listed in this medication guide.

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

You should not use this medication if you are allergic to ondansetron, to similar medicines such as dolasetron (Anzemet), granisetron (Kytril), or palonosetron (Aloxi). Do not take ondansetron if you are also using apomorphine (Apokyn).

To make sure you can safely take ondansetron, tell your doctor if you have any of these other conditions:

• liver disease;
• heart disease, congestive heart failure, a heart rhythm disorder;
• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood); or
• a personal or family history of Long QT syndrome.

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.

It is not known whether ondansetron passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

ondansetron 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 ondansetron?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. 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.

To use ondansetron oral soluble film (strip) (Zuplenz):

• Keep the strip in the foil pouch until you are ready to use the medicine.
• Using dry hands, remove the strip and place it on your tongue. It will begin to dissolve right away.
• Do not swallow the strip whole. Allow it to dissolve in your mouth without chewing.
• Swallow several times after the strip dissolves. If desired, you may drink liquid to help swallow the dissolved strip.
• Wash your hands after using Zuplenz.

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.

Your heart function may need to be tested with an electrocardiogram (ECG or EKG) on a regular basis. Do not miss any follow-up visits to your doctor.

Store at room temperature away from moisture and heat.

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 or call the Poison Help line at 1-800-222-1222.

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

What should I avoid while taking ondansetron?

Ondansetron may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be 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 a serious side effect such as:

• blurred vision or temporary vision loss (lasting from only a few minutes to several hours);
• severe dizziness, feeling short of breath, fainting, fast or pounding heartbeats;
• slow heart rate, trouble breathing;
• anxiety, agitation, shivering;
• feeling like you might pass out; or
• urinating less than usual or not at all.

Less serious side effects may include:

• diarrhea or constipation;
• weakness or tired feeling;
• fever;
• headache; or
• dizziness, drowsiness.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect ondansetron?

Tell your doctor about all other medicines you use, especially:

• arsenic trioxide (Trisenox);
• tacrolimus (Prograf);
• tramadol (Ultram, Ultracet);
• an antibiotic such as clarithromycin (Biaxin), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin, Pediazole), levofloxacin (Levaquin), moxifloxacin (Avelox), pentamidine (NebuPent, Pentam), or rifampin (Rifadin, Rimactane, Rifater);
• an antidepressant such as amitriptylline (Elavil, Vanatrip, Limbitrol), clomipramine (Anafranil), or desipramine (Norpramin);
• anti-malaria medications such as chloroquine (Aralen) or mefloquine (Lariam);
• heart rhythm medicine such as amiodarone (Cordarone, Pacerone), dofetilide (Tikosyn), disopyramide (Norpace), dronedarone (Multaq), ibutilide (Corvert), procainamide (Procan, Pronestyl), propafenone (Rythmol), quinidine (Quin-G), or sotalol (Betapace);
• medicine to prevent or treat nausea and vomiting such as dolasetron (Anzemet), droperidol (Inapsine), or ondansetron (Zofran);
• medicines to treat psychiatric disorders, such as chlorpromazine (Thorazine), clozapine (FazaClo, Clozaril), haloperidol (Haldol), pimozide (Orap), thioridazine (Mellaril), or ziprasidone (Geodon);
• migraine headache medicine such as sumatriptan (Imitrex, Treximet) or zolmitriptan (Zomig);
• narcotic medication such as methadone (Methadose, Diskets, Dolophine); or
• seizure medication such as carbamazepine (Carbatrol, Tegretol), phenytoin (Dilantin), or phenobarbital (Luminal).

This list is not complete and other drugs may interact with ondansetron. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about ondansetron.