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EspañolOndansetron overview
BRAND NAMES:
No brand names currently on the market
Generic Names:
Ondansetron
Uses:
Prevents nausea and vomiting due to cancer treatment or surgical procedures
Therapeutic Classes:
Antiemetic, serotonin/5HT3 receptor antagonist
Forms:
Tablet, orally dissolving tablet, oral solution, injection
How it’s taken:
By mouth or intravenous injection
What is Ondansetron used for?
Ondansetron prevents nausea and vomiting in persons undergoing chemotherapy or radiation therapy for cancer. It’s also given before or after surgery to prevent or relieve post-surgical nausea and vomiting.
What form(s) does Ondansetron come in
Tablet
4 mg
8 mg
24 mg
Orally disintegrating tablet
4 mg
8 mg
Oral solution (liquid)
4 mg/5 mL
Injection
2 mg/mL
What are common Ondansetron doses?
For the prevention of nausea and vomiting due to chemotherapy in adults
For highly emetogenic (nausea-causing) chemotherapy: 0.15 mg/kg given as an IV injection 3 times every four hours OR one 24 mg oral dose given 30 minutes before chemotherapy
For moderately emetogenic (nausea-causing) chemotherapy: 0.15 mg/kg given as an IV injection in up to 3 doses given four or eight hours apart OR 8 mg taken by mouth 30 minutes before chemotherapy, 8 mg taken 8 hours later, and 8 mg taken every 12 hours for one to two days
For the prevention of nausea and vomiting due to radiation therapy in adults
For total body irradiation: 8 mg taken orally one to two hours before each fraction
For single high-dose fraction irradiation of the abdomen: 8 mg taken orally one to two hours before irradiation and 8 mg taken orally every eight hours for one to two days following irradiation
For daily fractionated irradiation of the abdomen: 8 mg taken orally one to two hours before irradiation and 8 mg taken orally every eight hours
For the prevention of nausea and vomiting due to surgery in adults
16 mg oral dose given one hour before anesthesia OR 4 mg IV injection given immediately before anesthesia (the injection can also be given within 2 hours after surgery if the patient has not received anti-nausea treatment and experiences nausea and vomiting)
Ondansetron dosages are very complex since they are related to complex medical procedures. Children’s dosages will differ. Find more detailed information about Zofran (ondansetron) dosage, forms, and strengths here.
Common Ondansetron prescriptions
Ondansetron
4mg tablet disintegratingOndansetron
8mg tablet disintegrating
How to take Ondansetron
Your doctor will tell you how much medicine to use. Do not use more than directed.
How to take ondansetron tablets
Swallow the tablet whole with a glass of water. Do not cut or chew the tablet.
Store the tablets at room temperature.
How to take ondansetron orally disintegrating tablets
Read the illustrated instructions for use on the back of the box before taking this medicine.
Do not remove the tablet until you are ready to take it.
Before removing a tablet, make sure your hands are dry.
DO NOT PUSH the tablet through the foil.
Instead, peel back the foil and gently remove the tablet from the blister pack.
Immediately place the tablet on the top of your tongue. Do not cut or chew the tablet.
It will dissolve in seconds.
Swallow the disintegrated tablet with saliva. You do not need to drink water or other liquids.
Store ondansetron orally disintegrating tablets sealed in their blister pack in the original carton. Keep them at room temperature.
How to take ondansetron oral solution
Ondansetron oral solution does not need to be shaken before measuring out a dose.
Use a calibrated oral syringe when measuring out a dose. If you don’t have one, a pharmacist can provide one at no cost.
Store ondansetron oral solution upright in the original bottle. Keep it at room temperature protected from light.
What to do if you miss a dose of Ondansetron
Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose.
Do not take extra medicine to make up for a missed dose.
Ondansetron contraindications
This medicine is not right for everyone.
Do not use it if you have had an allergic reaction to ondansetron.
Ondansetron warnings
Tell any doctor or other healthcare provider who treats you that you are using this medicine.
Tell your doctor if you are pregnant or breastfeeding.
Tell your doctor if you have:
Liver disease
Congestive heart failure
Heart problems
Heart rhythm problems (such as prolonged QT interval or a slow heartbeat)
Low electrolyte levels
Stomach or bowel problems
This medicine may cause heart rhythm problems (such as QT prolongation) or other heart problems. Tell a doctor if you experience abnormal heartbeats (like palpitations or a slow heartbeat), chest pain, or chest tightness.
Ondansetron orally dissolving tablets may contain aspartame. Do not take these if you have a medical condition called phenylketonuria (PKU).
Ondansetron interactions
To avoid potentially hazardous drug interactions, tell the prescribing healthcare provider about all prescription drugs, over-the-counter medications, and supplements you use before taking ondansetron.
Tell other healthcare providers you are using this medicine before they prescribe new medications.
These first two rules are very important because a variety of drugs disturb the heart’s natural rhythm and could cause serious heart problems when taken with ondansetron. These include many commonly used antibiotics, psychiatric medications, cancer drugs, antiviral drugs, and so on. The list is very long, but doctors and other healthcare providers will recognize them.
Do not take ondansetron if you are also taking the Parkinson’s disease treatment apomorphine.
Some drugs may cause problems when they’re taken with ondansetron. Even though ondansetron therapy is brief, make sure the doctor knows if you’re taking:
Ondansetron can be taken with antacids.
Find out more about ondansetron interactions to avoid here.
Ondansetron side effects
Serious side effects
Talk to a doctor if you notice any signs or symptoms of a possible serious side effect including:
Fast, pounding, or uneven heartbeat
Chest pain, chest tightness, shortness of breath, lightheadedness, fainting
Anxiety, restlessness, fast heartbeat, rigid muscles, flushing, sweating, disorientation, overactive reflexes
Trouble breathing
Slurred speech, involuntary eye rolling, twitching, grimacing
Vision changes
Blistering, peeling, red skin rash
Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
Less serious side effects
Headache
Fatigue
Constipation
Diarrhea
Find more detailed information about Zofran (ondansetron) side effects here.
Sources:
Ondansetron hydrochloride injection prescribing information, NIH National Library of Medicine
Ondansetron hydrochloride orally disintegrating tablet prescribing information, NIH National Library of Medicine
Ondansetron hydrochloride solution prescribing information, NIH National Library of Medicine
Ondansetron hydrochloride tablet prescribing information, NIH National Library of Medicine