Consumer medicine information



ondansetron hydrochloride dihydrate tablets

Consumer Medicine Information

What is in this leaflet

Please read this leaflet carefully before you take Ondaz tablets.

This leaflet answers some common questions about Ondaz tablets. It does not contain all of the available information.

It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risks of you taking this medicine against the benefits they expect it will have for you.

If you have any concerns about taking this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine. You may need to read it again.

What Ondaz tablets are used for

Ondaz tablets contain a medicine called ondansetron. This belongs to a group of medicines called serotonin receptor-3 antagonists.

Ondaz tablets are used to help stop the nausea (sick feeling) and vomiting which can occur after medical treatments and operations.

Ondaz tablets should only be used to treat the nausea and vomiting for which they have been prescribed.

Ask your doctor if you have any questions about why this medicine has been prescribed for you. Your doctor may have prescribed it for another reason.

This medicine is not addictive.

Before you take Ondaz tablets

When you must not take it

Do not take this medicine if:

  • you have ever had an allergic reaction to ondansetron or to any of the other ingredients listed at the end of this leaflet under Product description
  • you are taking apomorphine (used to treat Parkinson’s disease)
  • you are pregnant, trying to become pregnant or breastfeeding, unless your doctor says it is safe
  • the expiry date (EXP) printed on the pack has passed
  • the packaging is torn or shows signs of tampering.

Before you start to take it

You must tell your doctor if:

  • you are allergic to any other medicines, foods, preservatives or dyes
  • you have had to stop taking another medicine for your nausea or vomiting
  • you are taking any other medicines, including any that you get without a prescription from your pharmacy, supermarket or health food shop
  • you have or used to have liver problems
  • you are breastfeeding, pregnant or trying to become pregnant.

Some medicines may affect the way others work. Your doctor or pharmacist will be able to tell you what to do when taking Ondaz tablets with other medicines.

How to take Ondaz tablets

How much to take

Take Ondaz tablets as directed by your doctor or pharmacist.

Do NOT take MORE TABLETS than your doctor or pharmacist tells you.

Do NOT take the tablets MORE OFTEN than your doctor or pharmacist tells you.

If you vomit within one hour of taking your first Ondaz tablet of each course prescribed to you, you should take the same dose again. If you continue to vomit, tell your doctor.

How to take it

Swallow each tablet with a drink of water. Do not crush the tablet. If you have trouble swallowing your tablet, please tell your doctor.

How long to take Ondaz tablets

Do not stop taking your medicine or change the dose without first checking with your doctor.

If you forget to take it

If you miss your dose and you do not feel sick, take your next dose when you are meant to.

If you miss your dose and you feel sick, take the missed dose as soon as possible, then go back to taking your Ondaz tablets as you would normally. If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

If you take too much (overdose)

Immediately telephone your doctor or the Poisons Information Centre (telephone 13 11 26) for advice, or go to Accident and Emergency at the nearest hospital, if you think that you or anyone else may have taken too much Ondaz tablets. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.

If you are not sure what to do, contact your doctor or pharmacist.

While you are taking Ondaz tablets

Things you must do

Tell your doctor if, for any reason, you have not taken your medicine exactly as directed. Otherwise, your doctor may think that it was not working as it should and change your treatment unnecessarily.

Things you must not do

Do not give your medicine to anyone else, even if their symptoms seem similar to yours.

Do not take Ondaz tablets to treat any other complaints unless your doctor tells you to.

Side effects

Check with your doctor as soon as possible if you think you are experiencing any side effects or allergic reactions due to taking Ondaz tablets, even if the problem is not listed below. Like other medicines, Ondaz tablets can cause some side effects. If they occur, they are most likely to be minor and temporary. However, some may be serious and need medical attention.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

The most commonly reported side-effects are:

  • headache
  • a sensation of warmth or flushing
  • mild stomach cramps
  • constipation or diarrhoea
  • dry mouth
  • hiccups
  • burning sensation at the site of injection.

These are all mild side effects. There is no immediate reason to stop taking your tablets unless you are concerned.

Tell your doctor immediately if you notice any of the following:

  • ‘wheezy’ symptoms
  • chest pain or tightness of the chest
  • changes in the way your heart beats, e.g. if you notice it beating faster or slower than normal, or if it beats irregularly or if it ‘throbs’
  • low blood pressure
  • fits or convulsions
  • swelling of the eyelids, face, lips, mouth or throat which may cause difficulty in swallowing or breathing
  • skin rash, skin lumps or hives.

These are all serious side effects. You may need urgent medical attention. Serious side effects are rare.

This is not a complete list of all possible side effects. Others may occur in some people and there may be some side effects not yet known.

If your nausea (feeling of sickness) or vomiting does not go away, ask your doctor what to do.

In certain illnesses and treatments where Ondaz has been used, blood vessel blockage has occurred. However, it is important to note that blood vessel blockage has also occurred in these illnesses and treatments when Ondaz tablets have NOT been used. Discuss this with your doctor if you have any concerns.

If you feel unwell or have any symptoms that you do not understand, you should tell your doctor immediately.

After taking Ondaz tablets


Keep it where children cannot reach it. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.

Keep your medicine in a cool dry place where the temperature stays below 30°C and keep it away from bright sunlight.

Do not store Ondaz tablets or any other medicine in the bathroom or near a sink. Do not leave it on a window sill or in the car. Heat and dampness can destroy some medicines.

Keep Ondaz tablets in their blister pack until time to take it.


If your doctor tells you to stop taking this medicine or the expiry date has passed, ask your pharmacist what to do with any medicine that is left over.

Product description

What it looks like

Ondaz comes in two types of tablets:

  • Ondaz 4mg – yellow, oval, film coated tablets with ‘GXET3’ engraved on one face and plain on the other.
  • Ondaz 8mg – yellow, oval, film coated tablets with ‘GXET5’ engraved on one face and plain on the other.

Available in blisters of 4 or 10 tablets.

Do NOT use your tablets if they have changed colour.


Active Ingredient:

  • Ondaz 4mg – 4mg ondansetron as ondansetron hydrochloride dihydrate
  • Ondaz 8mg – 8mg ondansetron as ondansetron hydrochloride dihydrate.

Your doctor will decide which strength you need.

Inactive ingredients:

  • hypromellose (464)
  • lactose
  • cellulose (460)
  • starch
  • magnesium stearate (572)
  • onaspray yellow (contains 171).

Your tablets also contain small amounts of citric acid, sodium citrate and sodium chloride.


Ondaz tablets are supplied in Australia by:
Sandoz Pty Ltd
ABN 60 075 449 553
19 Harris St
Pyrmont NSW 2009
Tel: 1800 634 500

Where to go for further information

Pharmaceutical companies are not in a position to give people an individual diagnosis or medical advice. Your doctor or pharmacist is the best person to give you advice on the treatment of your condition.

This leaflet was revised in January 2012.

Australian Register Number(s)
4mg tablets: AUST R 116396 (blisters)
8mg tablets: AUST R 116415 (blisters)

Published by MIMS August 2012