Generic Zofran [ONDANSETRON]

Ondansetron (on-DAN-se-tron) is used to prevent the nausea and vomiting that may occur after therapy with anticancer medicines (chemotherapy) or radiation, or after surgery.

Before Using This Medicine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For ondansetron, the following should be considered:

Allergies Tell your doctor if you have ever had any unusual or allergic reaction to ondansetron. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy Ondansetron has not been studied in pregnant women. However, this medicine has not been shown to cause birth defects or other problems in animal studies. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding It is not known whether ondansetron passes into the breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children This medicine has been tested in a limited number of children with cancer 6 months of age or older and after surgery in children 1 month to 12 years of age. In effective doses, the medicine has not been shown to cause different side effects or problems than it does in adults.

Older adults This medicine has been tested in a limited number of cancer patients 65 years of age or older and has not been shown to cause different side effects or problems in older people than it does in younger adults.

Other medicines Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other medical problems The presence of other medical problems may affect the use of ondansetron. Make sure you tell your doctor if you have any other medical problems, especially:

Abdominal surgery Use of ondansetron may cover up stomach problems
Allergy to selective 5-HT3 receptor antagonists (alosetron [e.g., Lotronex], dolasetron [e.g., Anzemet], granisetron [e.g., Kytril], palonosetron [e.g., Aloxi]) If you are allergic to one of these, you may be allergic to ondansetron because they are in the same group of medicines.
Liver disease Patients with liver disease may have an increased chance of side effects
Phenylketonuria (PKU) The oral disintegrating tablets may contain aspartame, which can make your condition worse.
Proper Use of This Medicine
If you vomit within 30 minutes after taking this medicine, take the same amount of medicine again. If vomiting continues, check with your doctor.

For patients using the oral disintegrating tablet form of this medicine:

Make sure your hands are dry.
Do not push the tablet through the foil backing of the package. Instead, gently peel back the foil backing and remove the tablet.
Immediately place the tablet on top of the tongue.
The tablet will dissolve in seconds, and you may swallow it with your saliva. You do not need to drink water or other liquid to swallow the tablet.
Dosing The dose of ondansetron will be different for different patients. Follow your doctor's orders or the directions on the label . The following information includes only average doses of ondansetron. If your dose is different, do not change it unless your doctor tells you to do so.

For oral dosage forms (solution, oral disintegrating tablets, and tablets):
For prevention of moderate nausea and vomiting after anticancer medicine:
Adults and children 12 years of age and older At first, the dose is 8 milligrams (mg) taken thirty minutes before the anticancer medicine is given. The 8-mg dose is taken again eight hours after the first dose. Then, the dose is 8 mg every twelve hours for one to two days.
Children 4 to 11 years of age At first, the dose is 4 mg taken thirty minutes before the anticancer medicine is given. The 4-mg dose is taken again four and eight hours after the first dose. Then, the dose is 4 mg every eight hours for one to two days.
Children up to 4 years of age Dose must be determined by your doctor.
For prevention of more severe nausea and vomiting after anticancer medicine:
Adults and children 12 years of age and older One 24-milligram (mg) tablet taken thirty minutes before the anticancer medicine is given.
Children up to 12 years of age Use and dose must be determined by your doctor.
For prevention of nausea and vomiting after surgery:
Adults Dose is usually 16 mg one hour before anesthesia (medicine to put you to sleep before surgery).
Children Dose must be determined by your doctor.
For prevention of nausea and vomiting after radiation treatment:
Adults At first, the dose is 8 mg taken one to two hours before radiation treatment. Then, the dose is 8 mg every eight hours.
Children Dose must be determined by your doctor.
For injection dosage form:
For prevention of nausea and vomiting after anticancer medicine:
Adults Dose is usually 32 mg injected into a vein, over a period of fifteen minutes, beginning thirty minutes before the anticancer medicine is given. Or, if the dose is based on body weight, it is usually 150 micrograms (mcg) per kilogram (kg) (68 mcg per pound) of body weight. This dose is injected into a vein over a period of fifteen minutes, beginning thirty minutes before the anticancer medicine is given. It is injected again four and eight hours after the first dose.
Children 6 months to 18 years of age Dose is based on body weight and must be determined by your doctor. It is usually 150 mcg per kg (68 mcg per pound) of body weight, injected into a vein over a period of fifteen minutes, beginning thirty minutes before the anticancer medicine is given. The dose is given again four and eight hours after the first dose.
Children up to 6 months of age Dose must be determined by your doctor.
For prevention of nausea and vomiting after surgery:
Adults Dose is usually 4 mg injected into a vein over a period of thirty seconds to five minutes. It is given just before anesthesia (medicine to put you to sleep before surgery) or right after surgery if nausea and vomiting begin.
Children 1 month to 12 years of age Dose is based on body weight and must be determined by your doctor. It is usually 100 mcg per kg (45.5 mcg per pound) of body weight for children weighing 40 kg or less (88 pounds or less), or 4 mg for children weighing over 40 kg (over 88 pounds). The dose is injected into a vein over a period of thirty seconds to five minutes. It is given just before anesthesia or after surgery if nausea and vomiting begin.
Children up to 1 month of age Dose must be determined by your doctor.
Missed dose If you miss a dose of this medicine, and you do not feel nauseated, skip the missed dose and go back to your regular dosing schedule. If you miss a dose of this medicine, and you feel nauseated or you vomit, take the missed dose as soon as possible.

Storage To store this medicine:

Keep out of the reach of children.
Store away from heat and direct light.
Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
Keep the medicine from freezing.
Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.
Side Effects of This Medicine
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Rare

Chest pain or discomfort; pain, redness, or burning at place of injection; shortness of breath; skin rash, hives, redness, and/or itching; tightness in chest; troubled breathing; wheezing

Incidence not known

Blurred vision; cold, clammy skin; confusion; coughing; decreased or irregular heartbeat; difficulty in breathing or swallowing; dizziness or fainting; dizziness, faintness, or lightheadedness when getting up from a lying position; fast, pounding, slow, or irregular heartbeat or pulse; fast, weak pulse; fixed position of eye; heart stops; hives or welts; hoarseness; inability to move eyes; increased blinking or spasms of eyelid; lab results that show problems with liver; large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs; lightheadedness; no breathing; no pulse or blood pressure; noisy breathing; pain in neck, back, or jaw; palpitations; shortness of breath; slow or irregular breathing; sticking out of tongue; sweating; swelling of face, throat, or tongue; trouble in breathing, speaking, or swallowing; unconscious; uncontrolled twisting movements of neck, trunk, arms, or legs; unusual facial expressions; weakness; weakness of arms and legs

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

More common

Constipation; diarrhea; fever; headache

Less common

Abdominal pain or stomach cramps; burning, tingling, or prickling sensations; dizziness or lightheadedness; drowsiness; dryness of mouth; feeling cold; itching; unusual tiredness or weakness

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.