Medically reviewed by Drugs.com. Last updated on Mar 25, 2022.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antiemetic
Pharmacologic Class: Serotonin Receptor Antagonist, 5-HT3
Uses for ondansetron
Ondansetron injection is used to prevent nausea and vomiting caused by cancer medicines (chemotherapy or radiation), including high-dose cisplatin. Ondansetron is also used to prevent and treat nausea and vomiting that may happen after surgery.
Ondansetron is available only with your doctor's prescription.
Before using ondansetron
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:
Tell your doctor if you have ever had any unusual or allergic reaction to ondansetron or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of ondansetron injection in children. However, safety and efficacy have not been established in children being treated for nausea and vomiting due to cancer treatments who are younger than 6 months of age or for the prevention of nausea and vomiting from surgery in children younger than 1 month of age.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of ondansetron injection in the elderly.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with 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. When you are receiving ondansetron, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using ondansetron with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using ondansetron with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Inotuzumab Ozogamicin
- Methylene Blue
- Morphine Sulfate Liposome
- Opium Alkaloids
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
- St John's Wort
Using ondansetron with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using ondansetron with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use ondansetron, or give you special instructions about the use of food, alcohol, or tobacco.
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:
- Allergy to selective 5-HT3 receptor antagonists (eg, alosetron [Lotronex®], dolasetron [Anzemet®], granisetron [Kytril®], or palonosetron [Aloxi®])—Use with caution. It is likely you will also be allergic to ondansetron.
- Bowel blockage or
- Gastric distension (enlarged stomach)—May cover up symptoms of these stomach or bowel problems, especially in patients who had a recent stomach surgery.
- Bradyarrhythmia (slow heartbeat) or
- Congestive heart failure or
- Electrolyte imbalance (eg, low potassium or magnesium in the blood)—Patients with these conditions should be monitored while using ondansetron.
- Heart rhythm problems (eg, congenital long QT syndrome)—Use is not recommended in patients with this condition.
- Heart rhythm problems (eg, prolonged QT interval)—Use with caution. May make this condition worse.
- Liver disease, severe—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper use of ondansetron
A nurse or other trained health professional will give you or your child ondansetron in a medical facility. Ondansetron is given as a shot into one of your muscles or through a needle placed in one of your veins.
When ondansetron is used to prevent nausea and vomiting caused by cancer medicines (chemotherapy), it is usually given 30 minutes before the start of chemotherapy for at least 15 minutes. Additional doses may be given 4 hours after the first dose and 8 hours after the first dose.
When ondansetron is used to prevent nausea and vomiting caused by surgery, it is usually given just before anesthesia (medicine to put you to sleep before surgery) or right after surgery if nausea and vomiting begin.
Precautions while using ondansetron
Check with your doctor if severe nausea and vomiting continue after leaving the hospital or cancer treatment center.
Ondansetron may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and requires immediate medical attention. Call your doctor right away if you or your child have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after you receive the medicine.
Do not use ondansetron if you or your child are receiving apomorphine (Apokyn®). Using these medicines together may cause serious side effects.
Ondansetron can cause changes in heart rhythms, including QT prolongation. It may change the way your heart beats and cause fainting or serious side effects in some patients. Contact your doctor right away if you or your child have fast, pounding, or irregular heartbeats.
Check with your doctor right away if you have anxiety, restlessness, a fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, or seeing or hearing things that are not there. These may be symptoms of a serious condition called serotonin syndrome. Your risk may be higher if you also take certain other medicines that affect serotonin levels in your body.
Ondansetron may cause a serious heart problem called myocardial ischemia (low blood supply to the heart). Check with your doctor right away if you have chest pain or discomfort, nausea, pain or discomfort in the arms, jaw, back, or neck, sweating, trouble breathing, irregular heartbeat, or vomiting.
Check with your doctor right away if you or your child start to have pain or swelling in your stomach area. These may be signs of a serious stomach or bowel problem.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Ondansetron side effects
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 or nurse immediately if any of the following side effects occur:
- Chest pain, discomfort, or tightness
- pain, redness, or burning at the injection site
- skin rash, hives, redness, or itching
- trouble breathing
Incidence not known
- blistering, peeling, or loosening of the skin
- blurred vision
- cold, clammy skin
- dark-colored urine
- decreased or irregular heartbeat
- difficulty with breathing or swallowing
- dizziness or fainting
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying position
- fast, pounding, slow, or irregular heartbeat or pulse
- fast, weak pulse
- fixed position of the eye
- heart stops
- hives or welts
- inability to move the eyes
- increased blinking or spasms of the eyelid
- joint or muscle pain
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- light-colored stools
- no breathing
- no pulse or blood pressure
- noisy breathing
- overactive reflexes
- pain or discomfort in the arms, jaw, back, or neck
- poor coordination
- red irritated eyes
- red skin lesions, often with a purple center
- slow or irregular breathing
- sore throat
- sores, ulcers, or white spots in the mouth or on the lips
- sticking out of the tongue
- stomach pain or swelling
- swelling of the face, throat, or tongue
- talking or acting with excitement you cannot control
- trembling or shaking
- trouble with speaking or swallowing
- uncontrolled twisting movements of the neck, trunk, arms, or legs
- unusual facial expressions
- unusual tiredness or weakness
- weakness of the arms and legs
- yellow eyes or skin
Some 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. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Burning, tingling, or prickling sensations
- dryness of the mouth
- feeling cold
- stomach cramps
Incidence not known
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about ondansetron
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- Dosage information
- During pregnancy or Breastfeeding
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- Drug class: 5HT3 receptor antagonists
- Drug Information
- Ondansetron injection
- Ondansetron Oral, Oromucosal (Advanced Reading)
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