About Ondansetron 4 mg Tablet
Ondansetron 4 mg Tablet contains Ondansetron 4 mg. Ondansetron is an anti-sickness medicine. It is used to prevent nausea and vomiting caused by cancer chemotherapy, radiotherapy and surgery. Doctors may also prescribe it for vomiting from other causes. It is usually taken before the treatment and then for a short time afterwards, as directed by the doctor.
Uses of Ondansetron 4 mg Tablet
- Nausea and vomiting caused by chemotherapy
- Nausea and vomiting caused by radiotherapy
- Nausea and vomiting after surgery
Benefits
In nausea and vomiting
It helps stop you feeling sick and vomiting, so you can keep food, drinks and other medicines down and recover more comfortably.
Side effects
Most side effects are mild. Talk to your doctor if any of them bother you or do not go away.
Common
- Headache
- Constipation
- Feeling of warmth or flushing
- Tiredness
Get medical help if you notice
- Fast, slow or irregular heartbeat, fainting — seek medical help straight away
- Agitation, confusion, high temperature, sweating, shaking or muscle twitching — may be serotonin syndrome; seek emergency care
- Severe stomach pain or swelling, or no bowel movement — contact your doctor
- Allergic reaction: rash, swelling of the face or throat, wheezing — seek emergency care
How to use
Take it exactly as your doctor prescribed, with or without food. Swallow the tablet with water. If you have a mouth-dissolving form, place it on the tongue and let it dissolve before swallowing.
How it works
Ondansetron blocks serotonin (5-HT3) receptors in the gut and brain. Serotonin released during chemotherapy or surgery can trigger the vomiting reflex; blocking it reduces nausea and vomiting.
Safety advice
Alcohol Caution
No important interaction is known, but alcohol can worsen nausea. It is best avoided.
Pregnancy Consult your doctor
Some studies suggest a small risk of cleft lip or palate if used in the first three months. Use only if your doctor advises it.
Breastfeeding Consult your doctor
The labelling advises against breastfeeding while taking it. Ask your doctor before using it.
Driving Caution
It is not expected to affect driving, but it can occasionally cause dizziness. Do not drive if you feel affected.
Kidney Safe
No dose change is usually needed in kidney disease, according to the labelling.
Liver Caution
In moderate or severe liver disease, the daily dose is usually limited. Tell your doctor if you have liver disease.
If you miss a dose
If you miss a dose and feel sick, take it as soon as you remember. If it is nearly time for the next dose, skip the missed one. Do not take two doses together.
Quick tips
- Take it at the time your doctor advised, often before chemotherapy or surgery.
- Drink plenty of fluids and eat fibre-rich food to reduce constipation.
- Tell your doctor if you have heart rhythm problems or low potassium or magnesium.
- See a doctor if vomiting continues, or you cannot keep fluids down.
Substitutes
Same salts in the same strength from other makers. Only switch brands on your doctor's or pharmacist's advice; our pharmacist checks every order against the prescription.
Same salts, other strengths or forms
Fact box
- Chemical class
- Carbazole derivative
- Therapeutic class
- Gastrointestinal / antiemetic
- Action class
- Serotonin 5-HT3 receptor antagonist
- Habit forming
- No
- Prescription
- Required
Interactions with other medicines
Tell your doctor and pharmacist about every medicine, vitamin and herbal product you take.
| Medicine | What can happen |
|---|---|
| Apomorphine | Can cause a severe drop in blood pressure and fainting — must not be used together |
| Medicines that affect heart rhythm (some antiarrhythmics, antipsychotics, antibiotics) | Higher risk of an irregular heartbeat |
| SSRI or SNRI antidepressants and other serotonin-raising medicines | Rare risk of serotonin syndrome |
| Tramadol | Ondansetron may reduce its pain-relieving effect |
| Phenytoin, carbamazepine and rifampicin | May reduce the effect of ondansetron |
This page is general information to help you understand your medicine. It is not a substitute for advice from your doctor or pharmacist. Do not start, stop or change a medicine on your own.
Written by the Asthra Health Care team from the approved prescribing information (Ondansetron prescribing information (CDSCO-approved labelling); NICE BNF: ondansetron; EMA PRAC review on ondansetron use in pregnancy, 2019). Pharmacist review pending.