Ondansetron (Zofran) vs. Dramamine: What’s the difference?

  • Ondansetron (Zofran) and Dramamine (dimenhydrinate) are anti-nausea medications used for different conditions.
  • Ondansetron is used to prevent nausea and vomiting caused by cancer chemotherapy and to prevent vomiting and nausea after surgery.
  • Dramamine is used for prevention and treatment of symptoms associated with motion sickness including nausea, vomiting, and dizziness.
  • Brand names for ondansetron include Zofran, Zofran ODT, and Zuplenz.
  • Dramamine is a brand name for dimenhydrinate.
  • Dramamine is available over-the-counter (OTC).
  • Ondansetron and Dramamine belong to different drug classes. Ondansetron is a serotonin-3 (5-HT3) receptor antagonist, and Dramamine is an antihistamine.
  • Side effects of ondansetron and Dramamine that are similar include drowsiness and constipation.
  • Side effects of ondansetron that are different from Dramamine include headache, feeling unwell (malaise), fatigue, dizziness, diarrhea, and abnormal heart rate and rhythm.
  • Side effects of Dramamine that are different from ondansetron include blurred vision and dry mouth/nose/throat.

What are ondansetron and Dramamine?

Ondansetron is an anti-nausea medication most often used to prevent nausea and vomiting caused by cancer chemotherapy. Chemotherapy agents increase secretion of serotonin, which stimulates serotonin (5-HT3) receptors in the brain, causing nausea and vomiting. Ondansetron works by selectively blocking serotonin (5-HT3) receptors, reducing the effect of increased serotonin due to chemotherapy. It is also prescribed to prevent vomiting and nausea after surgery.

Dramamine is an antihistamine used as an anti-nausea medication (antiemetic) for prevention and treatment of symptoms associated with motion sickness including nausea, vomiting, and dizziness.

What are the side effects of ondansetron and Dramamine?


Side effects of ondansetron are

Some individuals may develop abnormal heart rate and rhythm.


These side effects may occur, but if any of them persist or worsen, contact your doctor or pharmacist immediately:

To relieve dry mouth, sugarless hard candy or gum, ice chips or water, or a saliva substitute can help.

If your doctor has directed you to use this medication, he or she has determined that the benefit to you outweighs the risk of side effects. Many people use this medication with no serious side effects.

Contact your doctor immediately if you have any serious side effects, including

Get medical help right away if you have any very serious side effects, including seizures.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:


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What is the dosage of ondansetron vs. Dramamine?


Dosing for adults:

  • Highly nauseating chemotherapy: 24 mg orally dissolved on tongue 30 minutes prior to start of a single-day chemotherapy.
  • Moderately nauseating chemotherapy: Take 8 mg tablet 30 minutes prior to chemotherapy and repeat in 8 hours, then 8 mg every 12 hours for 1 to 2 days after chemotherapy.
  • Radiation-induced nausea and vomiting: Take 8 mg orally 1 to 2 hours prior to radiation and every 8 hours after first dose, as needed.
  • Post-surgery nausea and vomiting: 16 mg orally 1 hour before anesthesia.

Dosing for children:

  • Moderately nauseating chemotherapy (12 years and older): 8 mg orally prior to chemotherapy and repeat in 8 hours, then 8 mg every 12 hours for 1 to 2 days after chemotherapy.
  • Moderately nauseating chemotherapy (4 to 11 years): 4 mg orally 30 minutes prior to chemotherapy and repeat in 4 and 8 hours after the first dose, then every 8 hours for 1 to 2 days after chemotherapy.
  • Not recommended for children under 4 years old.


Follow all directions on the product packaging. If your doctor has prescribed this medication, take it as directed. If you are uncertain about any of the information, consult your doctor or pharmacist.

Take this medication by mouth with or without food. Measure liquid forms of this medication using a special measuring device/spoon provided in the packaging. Do not use a household spoon because you may not get the correct dose. The chewable tablets should be chewed thoroughly before being swallowed.

The dosage is based on your age, medical condition, and response to treatment. Do not increase your dose or take this medication more often than directed.

To prevent motion sickness, take the first dose 30 to 60 minutes before starting activity such as travel.

Contact your doctor if your condition does not improve or if it worsens.

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What drugs interact with ondansetron and Dramamine?


Ondansetron and apomorphine should not be used together due to sudden lowering in blood pressure and loss of consciousness.

Phenytoin, carbamazepine, and rifampin can increase ondansetron elimination and decrease blood levels, possibly lowering the effects of ondansetron.

Dronedarone can increase blood levels of ondansetron by reducing its breakdown in the liver. This may increase side effects of ondansetron. This combination may also increase the risk of abnormal heartbeats.


Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.

Some products that may interact with this drug include antihistamines applied to the skin such as:

Tell your doctor or pharmacist if you are taking other products that cause drowsiness including:

  • alcohol,
  • other antihistamines (such as diphenhydramine),
  • drugs for sleep or anxiety such as:
  • muscle relaxants, and
  • narcotic pain relievers (such as codeine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

This medication may interfere with certain laboratory tests (including allergy skin test), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

Are ondansetron and Dramamine safe to use while pregnant or breastfeeding?


There are no adequate studies of ondansetron in pregnant women to determine its safe and effective use during pregnancy.

It is not known whether ondansetron enters breast milk; therefore, it is best to be cautious before using this medication while breastfeeding.


During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.

Medically Reviewed on 7/24/2019



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