Ondansetron (Zofran)
4 mg
Stop: Call 911 or get emergency help
Fainting/near-fainting or fast/pounding/uneven heartbeat; chest pain/pressure; rash/hives or swelling; severe agitation/confusion, hallucinations, shaking, stiff muscles, heavy sweating or high fever; blurry or briefly lost vision.
What it may treat & how much to take
- 1
Stomach bug
Vomiting, watery diarrhea, cramps, low fever; often after contact with someone sick.
Take 1 tablet every 8 hours as needed. Stop when fluids stay down.
- 2
Food poisoning
Vomiting a few hours after food; cramps; may have diarrhea.
Take 1 tablet every 8 hours as needed. Stop when fluids stay down.
- 3
Bad nausea + traveler's diarrhea
Watery diarrhea; cannot keep pills/fluids down.
Ciprofloxacin: 1 tablet twice daily for 3 days. OR ondansetron every 8 hours as needed. Also take azithromycin.
- 4
Nausea with migraine
One-sided headache + nausea; light/noise bothers you.
Take 1 tablet every 8 hours as needed. Take usual headache medicine too, if prescribed.
How to take it
May take before nausea-causing activities. Maximum 3 tablets daily. Once nausea eases, drink small amounts often and use oral rehydration drink.
Important information
Get medical care for severe belly pain, abnormal vomit/stool, high fever, dehydration, continued vomiting, or worsening. It can hide a blocked/twisted gut.
Common side effects
Headache, constipation, tired, warm/flushed, dizzy.
Do not take if
Allergic to ondansetron or similar drug; long QT syndrome; taking apomorphine.
Ask your provider or pharmacist first if
Heart failure, irregular heartbeat, low potassium/magnesium, water pill, liver disease, or interacting heart-rhythm or serotonin medicines.
If pregnant or breastfeeding
Call a doctor first. If you cannot keep fluids down, get care instead of self-treating over 1 day. Ask before breastfeeding.