Ondansetron ODT is in the class of medications called serotonin 5-HT₃ receptor antagonists. It works on the body’s natural chemicals that are responsible for nausea.

Chemotherapy and radiation therapy cause the release of serotonin 5-HT₃, a neurotransmitter in the central nervous system that triggers the nerves that bring about the vomiting reflex. Serotonin 5-HT₃ receptor antagonist medication- such as Ondansetron ODT- blocks serotonin from reaching the nerves. This prevents feelings of nausea or the need to vomit.

While adverse reactions to ondansetron ODT are uncommon, some patients who take the drug may experience mild side effects, including:

• Headache
  
• Constipation
  
• Weakness
  
• Tiredness
  
• Chills
  
• Drowsiness
  

If any of the side effects above are severe or do not go away, you should contact your doctor. Rare, more serious side effects may occur. If you experience any symptoms listed below, contact your doctor right away.

• blurred vision or vision loss
• Rash or hives
• swelling of the eyes, face, lips, tongue, throat, hands, feet, ankles, or lower legs
• difficulty breathing or swallowing
• chest pain
• seizures

Because ondansetron can cause drowsiness and dizziness, especially when you first start taking it, it is advised to avoid driving or operating machinery until you know how the drug may affect you. This is not a complete list of ondansetron’s side effects. For more information on advice effects associated with ondansetron, please visit the National Institutes of Health’s DailyMed webpage.

Because ondansetron ODT is an orally disintegrating tablet, it should be placed on the top of the tongue and dissolved with saliva, rather than swallowed whole.

Adults with cancer are typically given 24 mg 30 minutes before the start of chemotherapy. Additional doses are sometimes given after the chemotherapy if needed.

For more moderate post-chemotherapy nausea and vomiting, 8 mg is given 30 minutes before starting cancer treatment. The 8 mg dose is taken again 8 hours after the first dose. Then, the dose is 8 mg every 12 hours for 1 to 2 days.

Patients undergoing radiotherapy are typically given 8 mg 1-2 hours before radiotherapy.

Patients undergoing surgery are typically given 16 mg 1 hour before receiving anesthesia.

Ondansetron ODT is currently only available via prescription. This means the use of this drug must be authorized by a licensed health care provider.

Looking for a prescription? Good news! Providers on Sesame can write a prescription – or refill an existing one – during a virtual or in-person visit. Depending on the medication, you can arrange for same-day pickup at a pharmacy near you. Book an online consultation with a real, licensed provider on Sesame today to determine whether or not ondansetron ODT is right for you.

Note that all prescriptions are at the discretion of your health care provider. Providers on Sesame cannot prescribe controlled substances.

Yes! Talk to a provider on Sesame and get your online doctor prescription or refill ordered right away for fast and convenient pickup from a pharmacy of your choice.

Note that all prescriptions are at the discretion of your clinician.