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Compare Zofran vs. Phenergan

Head-to-head comparisons of medication uses, side effects, warnings, and more.

Key takeaways

Ondansetron (Zofran) and promethazine (Phenergan) are both used to treat nausea and vomiting, but they work in different ways and have different uses. Ondansetron is an antiemetic that blocks serotonin in the brain, while promethazine is an antihistamine that also blocks dopamine and acetylcholine. Ondansetron is often used after surgery or cancer treatments, and it comes in various forms like tablets, dissolvable tablets, and injections. Promethazine, on the other hand, is used for a wider range of conditions, including allergies, motion sickness, and as a sedative before surgery. It is available as tablets, syrup, suppositories, and injections. Ondansetron can be used in children as young as 4 years old, while promethazine should not be given to children under 2 years old due to the risk of serious breathing problems. Both medications can cause drowsiness, but promethazine has a higher risk of causing excessive sleepiness and other side effects like dizziness and confusion.

  • Ondansetron (Zofran)
    Promethazine
  • Ondansetron (Zofran)
    Promethazine

  • Summary of Zofran vs. Phenergan

    Summary for Antiemetic
    Prescription only

    Ondansetron (Zofran) is an antiemetic (or anti-nausea) medication. It's used to prevent nausea and vomiting after surgery or cancer treatments. It works by stopping a chemical called serotonin from binding to receptors in the brain that cause the feeling of nausea and vomiting. Ondansetron (Zofran) is taken by mouth, typically every 8 to 12 hours. It comes in different formulations, including orally disintegrating tablet (ODT) and oral solution. It can also be given as injection by a healthcare professional (HCP) in a hospital setting. Side effects of this medication include headache, tiredness, and constipation or diarrhea.

    Summary for Antihistamine
    Prescription only

    Promethazine is a prescription medication with many uses, such as treatment or prevention of nausea, motion sickness, and allergy symptoms. Promethazine works by blocking several chemicals, including histamine, dopamine, and acetylcholine. It comes as tablets, an oral solution, rectal suppositories, and an injection. The dose of promethazine and how often you take it depends on your age and what medical condition you're taking it to treat. But it shouldn't be given to children younger than 2 years of age since it can cause serious breathing problems. Common side effects include sleepiness and dizziness.

  • Indications of Zofran vs. Phenergan

    Indications for
    •Prevention of nausea and vomiting due to cancer medications (chemotherapy) or radiation therapy
    •Prevention of nausea and vomiting after surgery
    Indications for
    •Runny nose, watery eyes, and other symptoms of allergies
    •Runny or stuffy nose that isn't caused by allergies
    •Rash, swelling, anaphylaxis, and other symptoms of an allergic reaction
    •Dermographism
    •Treatment or prevention of nausea and vomiting before and after surgery
    •Treatment or prevention of motion sickness
    •Treatment of pain along with other pain medications after surgery
    •Help to relax your body and produce a light sleep, particularly before a procedure

  • Pros and Cons of Zofran vs. Phenergan

    Pros and Const for Antiemetic
    Pros
    •Can use for both adults and children
    •Available as a lower-cost generic
    •Available as a liquid, dissolvable tablet, and injection for people who have problems swallowing pills or are too nauseous to keep medication down
    •Possible option during pregnancy and breastfeeding
    Cons
    •Needs to be taken multiple times daily
    •Might cause headache
    •Can interact with certain medications, like antidepressants and migraine medications
    •Not the best option for people who are at risk for stomach or gut blockages (bowel problems)
    Pros and Const for Antihistamine
    Pros
    •Available as a lower-cost generic
    •Available in different formulations, such as a tablet, syrup, and injection
    •Starts working within 20 minutes
    Cons
    •Can't be taken by children under 2 years old because risk of serious breathing problem
    •Higher risk of side effects in older adults
    •Can cause sleepiness

  • Common Side Effects of Zofran vs. Phenergan

    Common Side Effects for
    •Headache (up to 24%)
    •Fatigue (up to 13%)
    •Constipation (up to 9%)
    •Diarrhea (up to 6%)
    Common Side Effects for
    •Feeling drowsy or tired
    •Dizziness
    •Confusion
    •Dry mouth
    •Nervousness
    •Blurry vision

    The following side effects are those additionally reported with promethazine injection at the injection site:

    •Burning
    •Pain
    •Rash
    •Swelling

  • Warnings of Zofran vs. Phenergan

    Common Side Effects for
    •Severe allergic reactions
    •Life-threatening abnormal heart rhythm (QT prolongation)
    •Serotonin syndrome
    •Risk of heart attack
    •Masking of gut blockage and stomach bloating
    •Caution use in people with phenylketonuria (PKU) - orally disintegrating tablets only
    Common Side Effects for
    •Potentially life-threatening slow breathing (respiratory depression)
    •Serious tissue injury (Injection only)
    •Excessive sleepiness
    •Worsening of certain health problems
    •Seizures
    •Higher risk of infection (from low white blood cell count)
    •Risk of serious nerve problems (neuroleptic malignant syndrome)
    •Uncontrollable body movements

  • Prices with our coupons for Zofran vs. Phenergan

    Learn more about Ondansetron
    Learn more about Promethazine

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