Ondansetron
Stomach and refluxAlso known as Zofran
Ondansetron treats nausea and vomiting by blocking serotonin signals in your gut and brain that trigger the urge to be sick. It's often used after surgery, during chemotherapy, or for stomach bugs when nothing will stay down. It comes as regular tablets and as dissolvable tablets that melt on your tongue — handy when even swallowing water is a gamble.
How to take it
When
Take it exactly as prescribed — often on a schedule around chemo or surgery, or as needed for nausea.
Food
Works with or without food. Once the nausea eases, small bland sips and bites are a gentler restart than a full meal.
Handle with care
For dissolvable tablets, don't push them through the foil — peel the backing off and lift the tablet out with dry hands, then let it melt on your tongue.
Tell your doctor
Mention all antidepressants and migraine medicines you take — combining them with ondansetron can rarely cause serotonin syndrome.
Missed a dose?
If you're on a schedule and miss a dose, take it as soon as you remember — unless your next dose is soon, then skip it. Never take a double dose.
Common side effects
- Constipation
- Headache
- Tiredness or drowsiness
- Dizziness
Call a doctor if
- Fainting, a racing or fluttering heartbeat, or feeling like your heart is skipping — this medicine can affect heart rhythm. Get help now.
- Agitation, fever, sweating, fast heartbeat, muscle twitching, or confusion — possible serotonin syndrome, especially with antidepressants. Get help now.
- Rash, swelling of the face or throat, or trouble breathing — call emergency services.
- No urine or very little urine, or severe belly swelling and pain — call your doctor right away.