Zofran – Ondansetron uses, dose and side effects


4 mg and 8 mg film-coated tablets / 0.8 mg/ml oral solution

What Zofran is and what it is used for


Zofran is given preventively and as a treatment for nausea and vomiting in connection with chemotherapy, radiotherapy, or surgery.


Zofran is given preventively and as a treatment for nausea and vomiting in connection with chemotherapy for children who are 6 months and older and in connection with surgery for children who are 1 month and older.

The ondansetron found in Zofran may also be approved to treat other conditions not listed in this leaflet. Ask your doctor, pharmacist, or other healthcare professional if you have any further questions, and always follow their instructions.

What you need to know before you use Zofran

Do not use Zofran

  • if you are allergic to ondansetron or any of the other ingredients of this medicine (listed in section 6).
  • if you are using apomorphine, a medicine used for Parkinson’s disease.

Warnings and precautions

Talk to your doctor, pharmacist, or nurse before using Zofran: 

  • if you have impaired liver function, blockage, or obstruction in the intestine (intestinal obstruction)
  • if you have heart problems and if you are taking any medicines for this problem
  • if you are hypersensitive to other anti-nausea and vomiting medicines
  • if you are elderly, then experience in treating the elderly is limited.

Talk to your doctor or pharmacist immediately if you develop any of the following symptoms during or after treatment with Zofran:

  • if you experience sudden chest pain or pressure in the chest (myocardial ischemia).

Contact your doctor if you experience breathing problems, as breathing problems can be a precursor to a hypersensitivity reaction.

Other medicines and Zofran

Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines, including those obtained without a prescription, including (traditional) herbal medicines and herbal medicines. The effect of treatment can be affected if Zofran and other medicines are taken at the same time.

You must inform your doctor if you are using any of the following medicines as they may affect the effectiveness of the treatment:

  • phenytoin , carbamazepine – used in epilepsy
  • tramadol – pain reliever drug
  • rifampicin – used for tuberculosis
  • fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram, escitalopram ( SSRI drugs) – used to treat depression and/or anxiety
  • venlafaxine, duloxetine ( SNRI medicines) – used to treat depression and/or anxiety.

Concomitant use of Zofran and drugs that can cause EKG changes may lead to more pronounced EKG changes.

Simultaneous use of Zofran and medicines that can cause heart problems (eg anthracyclines ) can increase the risk of rhythm disturbances.

Therefore, consult your doctor if you are using other medicines before starting treatment with Zofran.

Pregnancy and breastfeeding

If you are pregnant or breastfeeding, think you may be pregnant, or are planning to have a baby, ask your doctor or pharmacist for advice before using this medicine.


You should not use Zofran during the first three months of pregnancy (first trimester). The reason is that Zofran may slightly increase the risk of a child being born with a cleft lip and/or cleft palate (opening or splitting in the upper lip or palate). If you are already pregnant, think you may be pregnant, or are planning to have a baby, ask your doctor or pharmacist for advice before taking Zofran. If you are a woman of childbearing age, you may be advised to use contraception.


A breastfed child may be affected. Therefore, do not use Zofran during breastfeeding other than on a specific prescription from a doctor.

Driving ability and use of machinery

Some side effects (impaired vision and feeling dizzy) may occur that affect driving or using machines.

You are responsible for assessing whether you are fit to drive a motor vehicle or perform work that requires increased attention. One of the factors that can affect your ability in these respects is the use of drugs due to their effects and/or side effects. A description of these effects and side effects can be found in other sections. Read all the information in this leaflet for guidance. Discuss with your doctor or pharmacist if you are unsure.

Zofran film-coated tablets contain lactose

If you have an intolerance to certain sugars, you should consult your doctor before taking this medication.

Zofran oral solution contains sorbitol

Sorbitol is a source of fructose. If you (or your child) have an intolerance to certain sugars, or if you (or your child) have been diagnosed with hereditary fructose intolerance, a rare, inherited disease that makes it impossible to break down fructose, consult a doctor before using this medicine. Sorbitol can cause stomach/intestinal discomfort and can have a mild laxative effect.

Zofran oral solution contains alcohol

This medicine contains small amounts of ethanol (alcohol), less than 100 mg per dose.

Zofran oral solution contains sodium

This medicine contains less than 1 mmol (23 mg) of sodium per dose unit (5ml), i.e. it is almost “sodium-free”.

How to use Zofran

Always use this medicine as directed by your doctor. Ask your doctor or pharmacist if you are unsure.

Nausea and vomiting caused by chemotherapy or radiotherapy


The dose of ondansetron can be varied within the range of 8-32 mg per day, either by injection or orally. The usual starting dose is 8 mg of ondansetron as a slow intravenous injection directly before chemotherapy and then you can receive an additional dose of 8 mg to a maximum daily dose of 32 mg. After one day, you can receive 8 mg of Zofran 2 times daily for 2-5 days. In the case of radiotherapy, you can be given 8 mg 2-3 times a day during the entire treatment period and then for another 2-5 days.

Children and adolescents (aged 6 months to 17 years):

Nausea and vomiting caused by chemotherapy in children and adolescents. Dose one is individual and is calculated by the doctor based on the child’s weight or body surface area.

Zofran is given as an injection immediately before chemotherapy and must not exceed 8 mg. Oral dosing can be started 12 hours later and continued for up to 5 days. The total daily dose must not exceed the maximum adult dose of 32 mg.

Treatment and prevention of nausea and vomiting after surgery

Adults, prevention and treatment:

The usual dose is 4-8 mg one hour before anesthesia. Your doctor may have decided to give the medicine as an injection.

Elderly, prevention and treatment:

Experience in the treatment of postoperative nausea in elderly patients is limited. However, Zofran is well tolerated by patients over 65 years of age during chemotherapy and radiotherapy.

Children and adolescents (aged 1 month to 17 years), prevention and treatment:

No studies have been conducted on the use of Zofran tablets or Zofran oral suspension to prevent or treat nausea or vomiting after surgery. Slow intravenous injection is recommended for this purpose.

Impaired liver function:

The daily dose should not exceed 8 mg if you have moderate to severely impaired liver function.

If you have used too much Zofran

If you or your child has taken too much medicine or if e.g. a child has accidentally ingested the medicine, you must immediately contact a doctor or hospital for an assessment of the risk and advice. Take the medicine package with you if you go to the hospital.

Symptoms of overdose:

Possible are blurred vision, double vision, dizziness, headache, fatigue, fast or slow heartbeat, low blood pressure, severe constipation, involuntary muscle spasms, muscle twitching, restlessness, overactivity, and hallucinations.

If you forget to use Zofran

Do not take a double dose to make up for a missed dose.

If you stop using Zofran

Do not stop taking your medicine without consulting your doctor, even if you feel well.

If you have further questions about this medicine, contact your doctor or pharmacist.

Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

Some side effects can be serious

STOP taking Zofran and contact your doctor immediately or go to the nearest emergency department if you or your child experience the following symptoms:

Serious allergic reactions:

  • hypersensitivity reaction with fever, rash, swelling, and sometimes a drop in blood pressure (anaphylactic shock, rare)
  • severe widespread skin damage (skin peeling of the epidermis and superficial mucous membranes), (toxic epidermal necrolysis, very rare occurrence).

Myocardial ischemia

Signs include:

  • sudden chest pain or
  • pressure over the chest

Other possible side effects:

Other side effects that may occur are listed below. Tell the doctor, pharmacist, or nurse if these side effects become severe.

Very common (may affect more than 1 in 10 users):

  • headache.

Common (may affect up to 1 in 10 users):

  • the feeling of warmth, hot flushes
  • constipation
  • local reactions at the injection site (in case of intravenous administration ).

Uncommon (may affect up to 1 in 100 users):

  • movement disorders, involuntary muscle twitching, and painful movements. Eye spasms when the eyes are forced in a certain direction, this can give a vertigo-like experience.
  • convulsions
  • irregular heartbeat or slow heartbeat
  • chest pain
  • low blood pressure
  • hiccup
  • elevated liver values ​​in liver function tests.

Rare (may affect up to 1 in 1,000 users):

  • hypersensitivity reaction
  • temporary vision changes, e.g. blurred vision (occurs mainly during injection treatment)
  • dizziness (in case of rapid injection administration).

Very rare (may affect up to 1 in 10,000 users):

  • transient blindness, usually transient within 20 minutes (occurs mainly with injection therapy).

How to store Zofran

Keep this medicine out of the sight and reach of children.

Oral solution: The bottle is stored upright at a maximum of 30 o C in protection against cold.

Use before the expiry date which is stated on the carton after EXP. The expiration date is the last day of the specified month.

Medicines must not be thrown into the drain or among the household waste. Ask the pharmacist how to dispose of medicines that are no longer used. These measures will help to protect the environment.

Contents of the packaging and other information

Contents declaration

Film-coated tablet

  • The active substance is ondansetron. 1 film-coated tablet contains ondansetron hydrochloride dihydrate corresponding to 4 mg and 8 mg ondansetron respectively.
  • Other ingredients are anhydrous lactose, magnesium stearate, microcrystalline cellulose, pregelatinized cornstarch, hypromellose, iron oxide (color E172), and titanium dioxide (color E171).

Oral solution

  • The active substance is ondansetron. 1 ml oral solution contains ondansetron hydrochloride dihydrate equivalent to 0.8 mg ondansetron.
  • Other ingredients are anhydrous citric acid, sodium citrate dihydrate, sorbitol, strawberry flavor (contains alcohol, less than 100 mg per dose ), sodium benzoate ( preservative E211), and purified water.

Appearance and package sizes of the medicine

Film-coated tablet

The film-coated tablets are yellow, oval, and marked GXET3 (4 mg tablets) and GXET5 (8 mg tablets) on one side.

Zofran 4 and 8 mg film-coated tablets respectively are available in blister packs of 10 and 50×1 tablets.

Not all pack sizes may be marketed.

Oral solution

50 ml in a yellow glass bottle with a child-resistant cap. Double-sided polypropylene measuring spoon for 2.5 and 5 ml included.

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