What is ondansetron orally disintegrating tablet. How does ondansetron work. What are the common side effects of ondansetron. When should you not take ondansetron. How to properly use ondansetron orally disintegrating tablets.

Understanding Ondansetron: A Powerful Antiemetic Medication

Ondansetron is a prescription medication belonging to a class of drugs known as antiemetics. These drugs are primarily used to prevent and treat nausea and vomiting associated with various medical treatments. Ondansetron works by blocking the action of serotonin, a neurotransmitter that plays a role in triggering nausea and vomiting reflexes in the body.

The orally disintegrating tablet form of ondansetron, available under the brand name Zofran ODT and as a generic medication, offers a convenient method of administration for patients who may have difficulty swallowing traditional tablets.

Forms and Availability of Ondansetron

Ondansetron comes in several forms to accommodate different patient needs:

• Oral tablets
• Orally disintegrating tablets
• Oral solution
• Intravenous (IV) form (administered by healthcare professionals only)

The availability of multiple forms ensures that patients can receive the medication in a manner that best suits their condition and preferences.

Primary Uses of Ondansetron Orally Disintegrating Tablets

Ondansetron orally disintegrating tablets are primarily prescribed to prevent nausea and vomiting associated with specific medical treatments. These include:

1. Chemotherapy
2. Radiation therapy
3. Surgery

By effectively managing these symptoms, ondansetron helps improve the quality of life for patients undergoing these challenging treatments.

How Does Ondansetron Work?

Ondansetron’s mechanism of action involves blocking the release of serotonin in the gut and central nervous system. This blockade prevents serotonin from triggering the nausea and vomiting reflex, effectively reducing these symptoms in patients.

Common Side Effects of Ondansetron

While ondansetron is generally well-tolerated, some patients may experience side effects. The most common side effects include:

• Headache
• Diarrhea
• Constipation
• Dizziness
• Drowsiness

These side effects are typically mild and often resolve on their own within a few days to weeks. However, if they persist or worsen, it’s important to consult with a healthcare provider.

Is ondansetron safe for long-term use?

Ondansetron is generally considered safe for short-term use as prescribed by a healthcare provider. Long-term use should be monitored closely by a doctor, as prolonged use may increase the risk of certain side effects. Your healthcare provider will weigh the benefits against potential risks when determining the appropriate duration of treatment.

Serious Side Effects and Warnings

While rare, ondansetron can cause serious side effects in some individuals. One of the most significant concerns is the risk of serotonin syndrome, a potentially life-threatening condition caused by excessive levels of serotonin in the body.

Symptoms of Serotonin Syndrome

Patients taking ondansetron should be aware of the following symptoms of serotonin syndrome:

• Agitation
• Hallucinations
• Rapid heartbeat
• Excessive sweating
• Fever
• Muscle rigidity
• Tremors
• Nausea and vomiting
• Diarrhea
• Confusion

If any of these symptoms occur, it’s crucial to seek immediate medical attention. Serotonin syndrome can be life-threatening if left untreated.

Drug Interactions with Ondansetron

Ondansetron can interact with various medications, potentially altering its effectiveness or increasing the risk of side effects. It’s essential to inform your healthcare provider about all medications, supplements, and herbal products you’re taking before starting ondansetron treatment.

Medications to Avoid with Ondansetron

Certain medications should not be taken concurrently with ondansetron due to the risk of dangerous interactions. These include:

• Apomorphine: Can cause a dangerous drop in blood pressure
• Certain antidepressants: May increase the risk of serotonin syndrome
• Some antipsychotic medications: Can potentially interact with ondansetron’s effects on the central nervous system

Always consult with your healthcare provider or pharmacist before starting or stopping any medication while taking ondansetron.

Proper Use of Ondansetron Orally Disintegrating Tablets

To ensure the maximum benefit and minimize potential side effects, it’s crucial to use ondansetron orally disintegrating tablets correctly. Here are some guidelines for proper use:

1. Take the tablet as prescribed by your healthcare provider
2. Allow the tablet to dissolve on your tongue; do not chew or swallow it whole
3. Take the medication with or without food, as directed
4. If you miss a dose, take it as soon as you remember, unless it’s close to the time for your next dose
5. Do not double up on doses to make up for a missed one

Can ondansetron be taken on an empty stomach?

Ondansetron can typically be taken with or without food. However, if you experience stomach upset when taking the medication on an empty stomach, it may be helpful to take it with a small meal or snack. Always follow your healthcare provider’s specific instructions regarding the timing of your ondansetron doses.

Special Considerations for Ondansetron Use

Certain groups of patients may need special consideration when using ondansetron. These include:

• Pregnant women
• Breastfeeding mothers
• Elderly patients
• Individuals with liver or kidney problems
• Patients with a history of heart rhythm disorders

If you fall into any of these categories, it’s essential to discuss the potential risks and benefits of ondansetron use with your healthcare provider before starting treatment.

Is ondansetron safe during pregnancy?

The safety of ondansetron during pregnancy has been a topic of ongoing research and debate. While some studies suggest a potential increased risk of certain birth defects, others have found no significant association. It’s crucial for pregnant women to consult with their healthcare provider to weigh the potential benefits against the risks when considering ondansetron use during pregnancy.

Alternatives to Ondansetron for Nausea and Vomiting

While ondansetron is an effective antiemetic medication, there are other options available for managing nausea and vomiting. Some alternatives include:

• Other antiemetic medications (e.g., metoclopramide, promethazine)
• Ginger supplements
• Acupressure wristbands
• Dietary modifications
• Behavioral techniques (e.g., relaxation exercises, distraction methods)

The most appropriate treatment option will depend on the underlying cause of nausea and vomiting, as well as individual patient factors. Always consult with a healthcare provider before starting or changing any treatment regimen.

Are there any natural alternatives to ondansetron?

While ondansetron is a prescription medication, some individuals may seek natural alternatives for managing nausea and vomiting. Ginger has shown promise in reducing nausea, particularly for pregnancy-related morning sickness and chemotherapy-induced nausea. Peppermint and chamomile tea may also provide some relief. However, it’s important to note that natural remedies may not be as potent or fast-acting as prescription medications like ondansetron. Always consult with a healthcare provider before using any alternative treatments, especially if you’re undergoing medical treatments that require effective antiemetic therapy.

Monitoring and Follow-up While Taking Ondansetron

Regular monitoring and follow-up are essential components of ondansetron treatment. Your healthcare provider may recommend:

1. Periodic blood tests to check liver function
2. Electrocardiograms (ECGs) to monitor heart rhythm, especially in patients with risk factors for heart problems
3. Regular check-ins to assess the medication’s effectiveness and any potential side effects
4. Adjustments to the dosage or treatment plan as needed

Open communication with your healthcare provider is crucial for ensuring the safe and effective use of ondansetron.

How often should patients on ondansetron have follow-up appointments?

The frequency of follow-up appointments for patients taking ondansetron can vary depending on individual circumstances. Generally, patients may have more frequent check-ins when first starting the medication or during active treatment periods (such as chemotherapy cycles). As treatment progresses and the patient’s response to ondansetron is established, follow-up appointments may become less frequent. Your healthcare provider will determine the appropriate schedule based on your specific medical needs and treatment plan.

Side Effects, Dosage, Uses, and More

Highlights for ondansetron

1. Ondansetron orally disintegrating tablet is available as a brand-name drug and as a generic drug. Brand name: Zofran ODT.
2. Ondansetron comes in three forms that you take by mouth: a tablet, a disintegrating tablet, and a solution. It’s also available in an intravenous (IV) form. This form is only given by a healthcare professional.
3. Ondansetron orally disintegrating tablet is used to prevent nausea and vomiting caused by certain medical treatments.

• Serotonin syndrome warning: Ondansetron raises your risk of a life-threatening condition called serotonin syndrome. This syndrome occurs when the chemical serotonin builds up too much in your body. A high level of serotonin can cause agitation, delirium (confused thinking) and hallucinations (seeing or hearing things that aren’t real). It can also cause sweating, rapid heartbeat, muscle stiffness, tremor, seizures, jerky muscle movements, and coma. Call your doctor right away if you have any of these symptoms. This condition can result from using ondansetron alone. However, it’s more likely to occur when you’re also taking another drug that affects serotonin levels.

Ondansetron is a prescription drug. It comes in three forms that you take by mouth: a tablet, a disintegrating tablet, and a solution. It’s also available in an intravenous (IV) form, which is only given by a healthcare professional.

Ondansetron orally disintegrating tablet is available as the brand-name drug Zofran ODT. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in every strength or form as the brand-name drug.

Ondansetron may be used as part of a combination therapy. This means you may need to take it with other medications.

Why it’s used

Ondansetron orally disintegrating tablet is used to prevent nausea and vomiting caused by certain medical treatments. These treatments include:

• chemotherapy
• radiation treatment
• surgery

How it works

Ondansetron belongs to a class of drugs called antiemetics. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions. Antiemetics are drugs that reduce nausea and vomiting.

Ondansetron works by blocking the release of the chemical serotonin in the gut and the central nervous system. This keeps serotonin from causing nausea and vomiting.

Ondansetron orally disintegrating tablet may cause drowsiness. It can also cause other side effects.

More common side effects

The more common side effects of ondansetron can include:

• headache
• diarrhea
• constipation
• dizziness
• drowsiness

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

• Serotonin syndrome. Symptoms can include:
  • agitation
  • hallucinations (seeing or hearing things that aren’t real)
  • rapid heartbeat
  • sweating
  • feeling hot
  • muscle rigidity (stiffness)
  • tremor
  • nausea
  • vomiting
  • diarrhea
  • coma

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare professional who knows your medical history.

Ondansetron orally disintegrating tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Examples of drugs that can cause interactions with ondansetron are listed below.

Drugs you should not use with ondansetron

Do not take these drugs with ondansetron. Doing so can cause dangerous effects in your body. Examples of these drugs include:

• Apomorphine. Taking this drug with ondansetron can cause your blood pressure to drop to unsafe levels. This can cause you to pass out.

Interactions that increase your risk of side effects from ondansetron

Taking ondansetron with certain medications raises your risk of side effects from ondansetron. This is because the amount of ondansetron in your body may be increased. Examples of these drugs include:

• Other drugs that affect serotonin levels, such as fluoxetine and paroxetine.

Interactions that can make ondansetron less effective

Taking these drugs with ondansetron can make ondansetron less effective. This is because the amount of ondansetron in your body may be decreased. Examples of these drugs include:

• Anti-seizure drugs, such as phenytoin or carbamazepine. Your doctor may switch you from ondansetron to a different drug if needed.
• Tuberculosis drugs, such as rifampin, rifabutin, or rifapentine. Your doctor may switch you from ondansetron to a different drug if needed.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare professional about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

This drug comes with several warnings.

Allergy warning

Ondansetron can cause a severe allergic reaction. Symptoms can include:

• flushing
• trouble breathing
• swelling of your throat or tongue
• dizziness
• coughing

If you develop these symptoms, call 911 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

Warnings for people with certain health conditions

For people with risk factors for heart arrhythmias: If you have conditions such as heart failure or congenital long QT syndrome, this drug may increase your risk of arrhythmias. Ask your doctor if you have risk factors for arrhythmias.

For people with phenylketonuria: The ondansetron orally disintegrating tablet contains phenylalanine. This amino acid can cause dangerous effects in people with a condition called phenylketonuria. Don’t take the orally disintegrating tablet if you have phenylketonuria.

Warnings for other groups

For pregnant women: There haven’t been enough studies done in humans to be certain how ondansetron might affect a fetus when the mother takes it. Research in animals has not shown a risk to the fetus. However, animal studies do not always predict the way humans would respond.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should only be used in pregnancy if clearly needed.

For women who are breastfeeding: Ondansetron may pass into breast milk and may cause side effects in a child who is breastfed. Talk to your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.

For seniors: The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

For children: This medication has not been studied in children younger than 4 years. It should not be used in children of this age range.

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

• your age
• the condition being treated
• how severe your condition is
• other medical conditions you have
• how you react to the first dose

Drug forms and strengths

Generic: Ondansetron

• Form: orally disintegrating tablet
• Strengths: 4 mg, 8 mg

Brand: Zofran ODT

• Form: orally disintegrating tablet
• Strengths: 4 mg, 8 mg
• Dosage for prevention of nausea and vomiting caused by chemotherapy

Adult dosage (ages 18–64 years)

• Typical dosage for chemotherapy that’s highly likely to cause nausea and vomiting: A single 24-mg dose given 30 minutes before chemotherapy.
• Typical dosage for chemotherapy that’s somewhat likely to cause nausea and vomiting: 8 mg, 30 minutes before chemotherapy. Eight hours later, you can take another 8 mg. For 1–2 days after chemotherapy, you can take 8 mg twice per day.

Child dosage (ages 12–17 years)

• Typical dosage for chemotherapy that’s somewhat likely to cause nausea and vomiting: 8 mg given 30 minutes before chemotherapy. Four and eight hours after the first dose, your child can take another 8 mg. For 1–2 days after chemotherapy, they can take 8 mg three times per day.

Child dosage (ages 4–11 years)

• Typical dosage for chemotherapy that’s somewhat likely to cause nausea and vomiting: 4 mg given 30 minutes before chemotherapy. Four and eight hours after the first dose, your child can take another 4 mg. For 1–2 days after chemotherapy, your child can take 4 mg, three times per day.

Child dosage (ages 0–3 years)

It has not been confirmed that ondansetron is safe and effective for use in children younger than 4 years. It should not be used in children of this age range.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Dosage for prevention of nausea and vomiting caused by radiation treatment

Adult dosage (ages 18–64 years)

• Typical dosage: 8 mg starting 1–2 hours before radiation, followed by 8-mg doses every 8 hours after that first dose. Continue for 1 to 2 days after you complete radiation treatment. This dosage may vary depending on the type of radiation you receive.

Child dosage (ages 0–17 years)

It has not been established that this drug is safe and effective for this use in children.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Dosage for prevention of nausea and vomiting caused by surgery

Adult dosage (ages 18–64 years)

• Typical dosage: 16 mg one hour before you receive anesthesia for surgery.

Child dosage (ages 0–17 years)

It has not been established that this drug is safe and effective for this use in children.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Special dosage considerations

For people with liver disease: If you have severe liver disease, you should not take more than 8 mg of ondansetron per day.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.

Ondansetron orally disintegrating tablet is used for short-term treatment. It comes with serious risks if you don’t take it as prescribed.

If you stop taking the drug suddenly or don’t take it at all: You could have nausea and vomiting that’s not controlled.

If you take too much: You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:

• faintness
• drowsiness
• agitation
• fast heartbeat
• flushing (sudden reddening of the skin)
• seizures

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 911 or go to the nearest emergency room right away.

How to tell if the drug is working: You should not have nausea or vomiting. If you do, it should be less severe.

Keep these considerations in mind if your doctor prescribes ondansetron for you.

General

• You can take ondansetron with or without food.
• Take this drug at the time(s) recommended by your doctor.
• Do not cut or crush the orally disintegrating tablets.

Storage

• Store the orally disintegrating tablets at a temperature between 36°F and 86°F (2°C and 30°C).
• Keep this drug away from light.
• Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

• Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
• Don’t worry about airport X-ray machines. They can’t harm your medication.
• You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
• Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Self-management

• When taking the orally disintegrating tablet out of its package, peel the foil back. Don’t try to push the tablet through the foil. This step will help keep the tablet from breaking.
• Place the tablet on your tongue. Leave it there for a few seconds to allow it to dissolve, and then swallow. You don’t need to take the tablet with liquid.

Availability

Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead to make sure your pharmacy carries it.

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

Side Effects, Dosage, Uses, and More

Highlights for ondansetron

1. Ondansetron orally disintegrating tablet is available as a brand-name drug and as a generic drug. Brand name: Zofran ODT.
2. Ondansetron comes in three forms that you take by mouth: a tablet, a disintegrating tablet, and a solution. It’s also available in an intravenous (IV) form. This form is only given by a healthcare professional.
3. Ondansetron orally disintegrating tablet is used to prevent nausea and vomiting caused by certain medical treatments.

• Serotonin syndrome warning: Ondansetron raises your risk of a life-threatening condition called serotonin syndrome. This syndrome occurs when the chemical serotonin builds up too much in your body. A high level of serotonin can cause agitation, delirium (confused thinking) and hallucinations (seeing or hearing things that aren’t real). It can also cause sweating, rapid heartbeat, muscle stiffness, tremor, seizures, jerky muscle movements, and coma. Call your doctor right away if you have any of these symptoms. This condition can result from using ondansetron alone. However, it’s more likely to occur when you’re also taking another drug that affects serotonin levels.

Ondansetron is a prescription drug. It comes in three forms that you take by mouth: a tablet, a disintegrating tablet, and a solution. It’s also available in an intravenous (IV) form, which is only given by a healthcare professional.

Ondansetron orally disintegrating tablet is available as the brand-name drug Zofran ODT. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in every strength or form as the brand-name drug.

Ondansetron may be used as part of a combination therapy. This means you may need to take it with other medications.

Why it’s used

Ondansetron orally disintegrating tablet is used to prevent nausea and vomiting caused by certain medical treatments. These treatments include:

• chemotherapy
• radiation treatment
• surgery

How it works

Ondansetron belongs to a class of drugs called antiemetics. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions. Antiemetics are drugs that reduce nausea and vomiting.

Ondansetron works by blocking the release of the chemical serotonin in the gut and the central nervous system. This keeps serotonin from causing nausea and vomiting.

Ondansetron orally disintegrating tablet may cause drowsiness. It can also cause other side effects.

More common side effects

The more common side effects of ondansetron can include:

• headache
• diarrhea
• constipation
• dizziness
• drowsiness

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

• Serotonin syndrome. Symptoms can include:
  • agitation
  • hallucinations (seeing or hearing things that aren’t real)
  • rapid heartbeat
  • sweating
  • feeling hot
  • muscle rigidity (stiffness)
  • tremor
  • nausea
  • vomiting
  • diarrhea
  • coma

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare professional who knows your medical history.

Ondansetron orally disintegrating tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Examples of drugs that can cause interactions with ondansetron are listed below.

Drugs you should not use with ondansetron

Do not take these drugs with ondansetron. Doing so can cause dangerous effects in your body. Examples of these drugs include:

• Apomorphine. Taking this drug with ondansetron can cause your blood pressure to drop to unsafe levels. This can cause you to pass out.

Interactions that increase your risk of side effects from ondansetron

Taking ondansetron with certain medications raises your risk of side effects from ondansetron. This is because the amount of ondansetron in your body may be increased. Examples of these drugs include:

• Other drugs that affect serotonin levels, such as fluoxetine and paroxetine.

Interactions that can make ondansetron less effective

Taking these drugs with ondansetron can make ondansetron less effective. This is because the amount of ondansetron in your body may be decreased. Examples of these drugs include:

• Anti-seizure drugs, such as phenytoin or carbamazepine. Your doctor may switch you from ondansetron to a different drug if needed.
• Tuberculosis drugs, such as rifampin, rifabutin, or rifapentine. Your doctor may switch you from ondansetron to a different drug if needed.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare professional about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

This drug comes with several warnings.

Allergy warning

Ondansetron can cause a severe allergic reaction. Symptoms can include:

• flushing
• trouble breathing
• swelling of your throat or tongue
• dizziness
• coughing

If you develop these symptoms, call 911 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

Warnings for people with certain health conditions

For people with risk factors for heart arrhythmias: If you have conditions such as heart failure or congenital long QT syndrome, this drug may increase your risk of arrhythmias. Ask your doctor if you have risk factors for arrhythmias.

For people with phenylketonuria: The ondansetron orally disintegrating tablet contains phenylalanine. This amino acid can cause dangerous effects in people with a condition called phenylketonuria. Don’t take the orally disintegrating tablet if you have phenylketonuria.

Warnings for other groups

For pregnant women: There haven’t been enough studies done in humans to be certain how ondansetron might affect a fetus when the mother takes it. Research in animals has not shown a risk to the fetus. However, animal studies do not always predict the way humans would respond.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should only be used in pregnancy if clearly needed.

For women who are breastfeeding: Ondansetron may pass into breast milk and may cause side effects in a child who is breastfed. Talk to your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.

For seniors: The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

For children: This medication has not been studied in children younger than 4 years. It should not be used in children of this age range.

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

• your age
• the condition being treated
• how severe your condition is
• other medical conditions you have
• how you react to the first dose

Drug forms and strengths

Generic: Ondansetron

• Form: orally disintegrating tablet
• Strengths: 4 mg, 8 mg

Brand: Zofran ODT

• Form: orally disintegrating tablet
• Strengths: 4 mg, 8 mg
• Dosage for prevention of nausea and vomiting caused by chemotherapy

Adult dosage (ages 18–64 years)

• Typical dosage for chemotherapy that’s highly likely to cause nausea and vomiting: A single 24-mg dose given 30 minutes before chemotherapy.
• Typical dosage for chemotherapy that’s somewhat likely to cause nausea and vomiting: 8 mg, 30 minutes before chemotherapy. Eight hours later, you can take another 8 mg. For 1–2 days after chemotherapy, you can take 8 mg twice per day.

Child dosage (ages 12–17 years)

• Typical dosage for chemotherapy that’s somewhat likely to cause nausea and vomiting: 8 mg given 30 minutes before chemotherapy. Four and eight hours after the first dose, your child can take another 8 mg. For 1–2 days after chemotherapy, they can take 8 mg three times per day.

Child dosage (ages 4–11 years)

• Typical dosage for chemotherapy that’s somewhat likely to cause nausea and vomiting: 4 mg given 30 minutes before chemotherapy. Four and eight hours after the first dose, your child can take another 4 mg. For 1–2 days after chemotherapy, your child can take 4 mg, three times per day.

Child dosage (ages 0–3 years)

It has not been confirmed that ondansetron is safe and effective for use in children younger than 4 years. It should not be used in children of this age range.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Dosage for prevention of nausea and vomiting caused by radiation treatment

Adult dosage (ages 18–64 years)

• Typical dosage: 8 mg starting 1–2 hours before radiation, followed by 8-mg doses every 8 hours after that first dose. Continue for 1 to 2 days after you complete radiation treatment. This dosage may vary depending on the type of radiation you receive.

Child dosage (ages 0–17 years)

It has not been established that this drug is safe and effective for this use in children.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Dosage for prevention of nausea and vomiting caused by surgery

Adult dosage (ages 18–64 years)

• Typical dosage: 16 mg one hour before you receive anesthesia for surgery.

Child dosage (ages 0–17 years)

It has not been established that this drug is safe and effective for this use in children.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, a higher amount of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dosage or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Special dosage considerations

For people with liver disease: If you have severe liver disease, you should not take more than 8 mg of ondansetron per day.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.

Ondansetron orally disintegrating tablet is used for short-term treatment. It comes with serious risks if you don’t take it as prescribed.

If you stop taking the drug suddenly or don’t take it at all: You could have nausea and vomiting that’s not controlled.

If you take too much: You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:

• faintness
• drowsiness
• agitation
• fast heartbeat
• flushing (sudden reddening of the skin)
• seizures

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 911 or go to the nearest emergency room right away.

How to tell if the drug is working: You should not have nausea or vomiting. If you do, it should be less severe.

Keep these considerations in mind if your doctor prescribes ondansetron for you.

General

• You can take ondansetron with or without food.
• Take this drug at the time(s) recommended by your doctor.
• Do not cut or crush the orally disintegrating tablets.

Storage

• Store the orally disintegrating tablets at a temperature between 36°F and 86°F (2°C and 30°C).
• Keep this drug away from light.
• Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

• Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
• Don’t worry about airport X-ray machines. They can’t harm your medication.
• You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
• Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Self-management

• When taking the orally disintegrating tablet out of its package, peel the foil back. Don’t try to push the tablet through the foil. This step will help keep the tablet from breaking.
• Place the tablet on your tongue. Leave it there for a few seconds to allow it to dissolve, and then swallow. You don’t need to take the tablet with liquid.

Availability

Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead to make sure your pharmacy carries it.

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects.