You should not use ondansetron if you are also using apomorphine (Apokyn).
You should not use ondansetron if you are allergic to it 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).
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 this medicine 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 ondansetron
You should not use ondansetron if:
you are also using apomorphine (Apokyn); or
you are allergic to ondansetron or similar medicines (dolasetron, granisetron, palonosetron).
To make sure ondansetron is safe for you, tell your doctor if you have:
liver disease;
an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);
congestive heart failure, slow heartbeats;
a personal or family history of long QT syndrome; or
a blockage in your digestive tract (stomach or intestines).
Ondansetron is not expected to harm an unborn baby. Tell your doctor if you are pregnant.
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.
Ondansetron is not approved for use by anyone 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 ondansetron 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.
Ondansetron 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 ondansetron 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.
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 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. Store liquid medicine in an upright position.
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.
