Zofran was a brand name for the generic medication, ondansetron. The brand name version is discontinued, but you can still get the generic option. Typically, ondansetron stays in your body for 24 hours, but this can vary.
Medically reviewed by Alexandra Perez, PharmD, MBA, BCGP
When waves of nausea hit, you’re likely looking for fast relief. Ondansetron can provide just that.
Ondansetron is a type of antiemetic medication known as a 5-HT3 receptor agonist that helps stop nausea and vomiting.
It works in two main ways. First, it blocks signals in the brain that can make you feel sick. It also works in the stomach and gut by calming the vagus nerve, which senses problems like stomach irritation.
Healthcare professionals might prescribe ondansetron to ease nausea and vomiting resulting from:
chemotherapy
radiation therapy
surgery
How long does ondansetron (Zofran) stay in your system?
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How long ondansetron stays in the body differs from person to person. After taking it, your body generally absorbs it within 1.5 hours.
After absorption, how long it remains in your body depends on different factors, including age, body weight, dosage, and food intake. In adults, the drug’s half-life is around 3–4 hours. In older adults, the half-life may be up to 5.5 hours.
The half-life is how long it takes your body to remove half of the medication. It generally takes 4–5 half-lives for your body to remove a drug completely.
This means ondansetron may stay in your body for up to 20 hours. For older adults, it may be up to 27.5 hours.
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Aside from your age, the following factors can affect the half-life of ondansetron and how long it stays in your system:
Dosage: Taking higher doses increases the amount of medication your body absorbs.
Liver health: If you have liver issues, you may need to take lower or fewer doses as your liver may not be able to break down the medication as quickly.
Body weight: Your body weight can affect how quickly your body metabolizes the drug. For this reason, the recommended dosage for children is based on their weight.
Food: Eating food with some oral medications can reduce how much your body absorbs.
Digestion: Individual variations in gut health also affect how fast your body processes medications.
Administration form: Receiving a medication intravenously (IV) may mean your body metabolizes it faster than taking it by mouth.
Although there are many factors at play, sticking to the dosage and timing recommendations from a prescribing healthcare professional is the safest approach to taking this medication.
How long it takes to work
After taking it by mouth, it takes your body around 1.5 hours to absorb ondansetron, providing quick relief from nausea and vomiting. You may even experience its benefits before this time.
Side effects
While ondansetron can be effective and without side effects, some people may experience some common side effects that include:
In addition to ondansetron, doctors may also prescribe the following medications to help treat nausea and vomiting:
Serotonin-receptor antagonists:Ondansetron is a type of serotonin-receptor antagonist. These drugs work by affecting serotonin levels in the brain. Alternatives to ondansetron include granisetron, dolasetron (Anzemet), and palonosetron (Aloxi).
Anticholinergics: These medications block the action of a neurotransmitter called acetylcholine and can be especially beneficial for motion sickness. One option is a skin patch called scopolamine (Transderm Scop).
Dopamine receptor antagonists: Drugs like prochlorperazine (Compro) block the action of dopamine in the brain.
If nausea is affecting your ability to function from day to day, consider talking with a healthcare professional about your treatment options.
They can help rule out underlying conditions and give you a breakdown of the pros and cons of anti-nausea and vomiting medications.
Summary
Zofran was the brand name for the generic medication, ondansetron. The brand name Zofran is discontinued, but the generic version is still available.
Ondansetron is an anti-nausea medication that relieves nausea and vomiting by blocking signals in the brain and calming the nerve in the stomach that causes the sensation.
After taking it orally, your body generally absorbs ondansetron within 1.5 hours.
How long it stays in your system depends on age, dosage, liver health, body weight, food intake, and administration form. Generally, ondansetron can stay in your system for up to 27.5 hours.
