What is Ondansetron? - Definition, Drug Class & Structure

Instructor: Alyssa Campbell

Alyssa is an active RN and teaches Nursing and Leadership university courses. She also has a Doctorate in Nursing Practice and a Master's in Business Administration.

Ondansetron is a popular medication used to treat the uncomfortable symptoms of nausea and vomiting. Read this lesson to learn more about when the drug is used, along with the classification and structure of this medication.

A New Medication

Suffering from nausea, stomach discomfort and queasiness, Amy visits the doctor hoping for some relief. After learning that her nausea is a common side effect of her chemotherapy treatment for cancer, the doctor suggests a new medication for her to try. Eager to be relieved of her unbearable nausea, she readily accepts the new prescription for ondansetron and has it filled.

What is Ondansetron?

Amy is taking chemotherapy, a powerful drug treatment prescribed to help combat her breast cancer. Unfortunately, the chemotherapy treatments make her nauseous and cause her to throw up. Now that she is taking the ondansetron for a few days, her nausea is beginning to subside and decrease.

Amy is a retired chemist, and continues to take pride in understanding how medications and treatments work. She begins researching her new medication, ondansetron, to learn more about the drug that lessens her discomfort. She learns that ondansetron is used to treat nausea and vomiting caused by:

  • Chemotherapy drugs
  • Surgery and use of anesthesia
  • Radiation, the use of high powered energy to target and destroy cancer cells

Drug Classification

Drug classifications are groups of drugs that are similar in chemical structure and alike in how they act inside the body. Ondansetron belongs to the class of serotonin receptor antagonists. This means that ondansetron acts to block nerves from receiving serotonin, a chemical in the body that can be found in the brain, blood, and gastrointestinal system.

The presence of serotonin and the absorption of this chemical by nerve receptors is known to cause nausea. Ondansetron, a serotonin receptor antagonist, blocks a specific serotonin-seeking receptor known as the 5-HT3 receptor. Hence, Amy learns that ondansetron was specifically designed to treat the symptoms caused by the absorption of serotonin through these receptors.

Medication Structure

After learning about how ondansetron works by blocking serotonin, an article regarding the structure of the medication piques her interest. As a retired chemist, she now seeks to understand the chemical structure of the drug. Chemical structure, or the arrangement of atoms and molecules, is the unique fingerprint of each drug affecting its action within the body.

The chemical structure of ondansetron consists of several molecular components, including:

  • Carbon
  • Nitrogen
  • Oxygen
  • Hydrogen

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account