Ondansetron Nursing Considerations – Drug Class & Structure

Are you looking for more information about Ondansetron? Ondansetron is a prescription medicine that prevents nausea and vomiting caused by cancer treatments such as chemotherapy, radiation therapy, and surgery.

This drug works by blocking the action of serotonin in the brain, which helps reduce nausea and vomiting. It’s drug name is ondansetron (Zofran).

In addition to preventing nausea and vomiting, ondansetron patient teaching about the side effects of its use. Knowing what potential side effects may occur can help patients better manage their symptoms while taking this medication.

Read this article to learn more about Ondansetron, including drug class, dose range, structure, etc.

Ondansetron Drug History

GlaxoSmithKline developed Ondansetron, known as Zofran, in London in the mid-1980s. In September 1987, it received its US patent protection and was granted a use patent in June 1988. The United States Food and Drug Administration (FDA) approved the drug in January 1991.

In November 1996, it was granted a divisional patent, and due to GlaxoSmithKline’s research on pediatric use, the patent protection was extended until December 2006. By its patent expiration in 2006, Zofran had become the twentieth highest-selling brand name drug in the United States, with sales of US$1.3 billion.

US Brand Name

  1. Zofran
  2. Zofran ODT
  3. Zuplenz

Zofran Nursing Consideration – Drug Class

If you’re a nursing student or new nurse, you’ve probably heard of Zofran, a popular antiemetic medication used to treat nausea and vomiting. But have you ever wondered exactly how it works? Understanding its pharmacologic class as a five HT3 antagonist may initially seem overwhelming. 

But, breaking it down reveals that “five HT3” refers to serotonin, a chemical in the brain that helps regulate mood, appetite, and nausea. By blocking the action of serotonin, Zofran can effectively treat nausea and vomiting. It’s easy to see how understanding the pharmacologic class can help nurses better understand how medications work and provide better care for their patients.


Ondansetron is a white to off-white crystalline powder slightly soluble in water. It has an empirical formula of C18H19N3O and a molecular weight of 293.36. It is available in tablet, oral fluid, and injection form.

Nursing Implication of Zafron

  • Cancer treatment: The 5-HT3 receptor antagonists are used primarily to treat nausea and vomiting caused by chemotherapy, radiation therapy, or surgery. 
  • Induced nausea and vomiting: Ondansetron prevents nausea and vomiting associated with cancer chemotherapy and radiation therapy.
  • Postoperative nausea and vomiting:  Ondansetron is used to reduce the occurrence of postoperative nausea and vomiting.
  • Gastroenteritis: Ondansetron is used to reduce the symptoms of gastroenteritis.
  • Cyclic vomiting syndrome: Ondansetron is sometimes used to reduce the symptoms of cyclic vomiting syndrome.

Nursing Implications for Zofran – Dose Range 

As a nurse, knowing the nursing implications of Zofran is essential. Zofran works by blocking certain chemicals in the body that trigger nausea and vomiting. So, what range is suitable for patients? Let’s understand with following data:

Nausea and Vomiting

Adult: PO 8 mg 30 min before chemotherapy, then q8h times 2 more doses

  • Adult/Child: IV 6 mo–18 y, 0.15 mg/kg or 32 mg infused over 15 min beginning 30 min before the start of chemotherapy
  • Child: PO >4 y, 4 mg 30 min before chemotherapy,
  • Nausea & Vomiting with Highly Emetogenic Chemotherapy

Adult: PO Single 24-mg dose 30 min before administration of single-day highly emetogenic chemotherapy

Postoperative Nausea and Vomiting

  • Adult: PO 8–16 mg 1 h preoperatively IM 4 mg injected immediately before anesthesia induction
  • Child: IV 1 mo–12 y, 0.1 mg/kg

Hyperemesis Gravidarum

  • Adult: PO/IV 4–8 mg 2–3 times per day

Hepatic Impairment

  • Maximum dose 8 mg/d PO/IV in patients with severely impaired liver function according to Child-Pugh criteria



These drugs are available only with your doctor’s prescription. It is available in the following forms:

  • Tablet, Disintegrating
  • Film
  • Tablet
  • Solution

When We Can Use

Ondansetron drugs are given to prevent or stop nausea/vomiting in a variety of situations:

  • Before Chemotherapy
  • After Surgery
  • After Radiation Therapy
  • When taking vital medicines that can cause nausea/vomiting
  • In patients with gastroenteritis
  • In pregnancy, to prevent hyperemesis gravidarum
  • To reduce the chance of acute and delayed nausea/vomiting after chemotherapy.

Ondansetron Side Effects

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

More Common Side Effects

The more common side effects of Ondansetron can include:

  • headache
  • constipation
  • diarrhea
  • drowsiness
  • dizziness

Less Common Side Effects

Less common side effects of Ondansetron can include:

  • rash
  • hives
  • itching
  • difficulty breathing or swallowing

Drugs you should not use with Ondansetron

You should not use certain drugs with Ondansetron. These include:

  • Apomorphine
  • fluoxetine
  • paroxetine
  • Anti-seizure drugs, such as phenytoin or carbamazepine.
  • Tuberculosis drugs, such as rifampin, rifabutin, or rifapentine.


  • Administering Ondansetron is easy and works best when given before chemotherapy or anesthesia.
  • The recommended administration time for IV push ondansetron is at least 30 seconds, although a slower administration time of 2-5 minutes is preferred.
  • Patients should be directed to notify their healthcare provider or physician if they see involuntary movements of the limbs, face, or eyes, an uneven heartbeat, or show signs of serotonin syndrome.
  • Disintegrating tablets and films must not be swallowed—it will dissolve and be swallowed with saliva instead. Make sure your patient understands this before taking the medication.
  • When disintegrating tablets, it’s essential to handle them with care. Always ensure your hands are dry before touching the tablet because any moisture will cause it to start dissolving prematurely.
  • And while disintegrating tablets and films can be a good option for patients who struggle with traditional pills, it’s important to stress that they should not swallow these medications.
  • Instead, the tablet will dissolve in their mouth with saliva, making it easier for their body to absorb the medication. However, it’s also important to note that not all ondansetron tablets are the disintegrating kind, so make sure you know what type you’re using before giving it to your patient.
  • Lastly, always avoid pushing the dissolvable Ondansetron through the blister pack, which could damage the fragile tablet. Instead, peel off the backing and remove the tablet carefully.

Final Thoughts

Ondansetron Nursing Considerations should be administered with caution to patients with hepatic impairment. It’s vital to ensure your patient understands how the disintegrating tablet or film works so it is swallowed properly.

Ondansetron patient teaching should include instructions to notify their healthcare provider or physician if they experience involuntary movements of the limbs, eyes, or face, an irregular heartbeat, or show symptoms of serotonin syndrome.

Lastly, always avoid pushing the dissolvable Ondansetron through the blister pack, which could damage the fragile tablet. Instead, peel off the backing and remove the tablet carefully.


  • https://en.wikipedia.org/wiki/Ondansetron#External_links
  • https://medlineplus.gov/druginfo/meds/a601209.html

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