Ondansetron - rectal

Patient Medicine Information
Why do I need this medicine?
Ondansetron is used to prevent nausea and vomiting caused by cancer chemotherapy or radiation therapy.
How do I use this medicine?
Use Ondansetron exactly as directed by your doctor or according to the instructions on the label. Do not use more or less than instructed by your doctor.

Suppositories are usually given when you are not able to swallow an oral medication, or the medicine cannot be injected directly into the vein.

The suppository is to be inserted into the rectum. Do not eat, chew or swallow it. Do not use it in any other way. Try to go to the toilet before you insert the suppository.

Follow these steps:
  1. Wash your hands thoroughly.
  2. Remove the suppository from the foil wrapper.
  3. If you are right-handed, lie on your left side and pull your right knee up to your chest.
  4. Gently insert the suppository with the pointed end first into your rectum. Gently push the suppository as far as it would go.
  5. Remain lying in this position for 10 -15 minutes to allow the suppository to melt. If you feel that the suppository is slipping out, press your buttocks together.
  6. Wash your hands.
  7. Try not to empty your bowels within 1 hour after inserting the suppository. The suppository must remain in the rectum so that the medicine can be absorbed.
The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the severity of your condition.
What should I do if I have forgotten to use this medicine?
If you miss a dose and still feel sick or feel like you might vomit, administer the missed dose as soon as you remember then return to your normal dosing schedule.

If you miss a dose but do not feel sick, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.
When should I not use this medicine?
Do not use Ondansetron if you ever had an allergic reaction (rashes, breathlessness, swollen eyes) to similar medicines such as granisetron and palonosetron.

Alert your doctor if you have a congenital long QT syndrome (heart disorder that is present from birth) as this medicine may not be suitable for you.

Do not use Ondansetron with apomorphine, a medicine used for Parkinson's disease.
What should I take note of while using this medicine?
Inform your doctor if you have the following conditions:
  • liver disease
  • heart disease e.g. fast and irregular heartbeat, heart failure
  • electrolyte imbalance (imbalance of minerals e.g. potassium, magnesium in the body)
  • bowel problems e.g. bowel obstruction
Let your doctor know if you are pregnant or breastfeeding.

For as long as you are using this medicine, you may need to have regular heart check-up or blood tests to check your body’s response to Ondansetron. Your doctor will advise you about how often you need to have these tests.

Some genetic traits can affect this medicine’s efficacy. Individuals who are ultrarapid metaboliser of CYP2D6 may respond poorer to this medicine. Although not routinely done, your doctor may advise you to take genetic testing to check if this medicine is best suited for you. If you know you have this gene type, inform your doctor.
What side effects could I experience?
Ondansetron may cause any of the following side effects: headache, flushing, tiredness, anxiety, constipation, hiccups and local burning sensation.

Some side effects may need immediate medical help. Alert your doctor immediately if you experience any of the following:
  • chest pain, shortness of breath, irregular heartbeat
  • uncontrollable movements such as twitching and jerking, fits or seizures
  • light headedness, loss of consciousness
  • rashes, breathlessness, swelling of the face, eyes or mouth
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I use this with other medicines?
Do not use Ondansetron with apomorphine, a medicine used for Parkinson's disease.

Inform your doctor and pharmacist if you are taking any of these medicines:
  • medicines for heart disease or high blood pressure e.g. amiodarone, atenolol, timolol
  • medicines for epilepsy (seizures or fits) e.g. carbamazepine, phenytoin
  • medicines for depression e.g. mirtazapine, fluoxetine, sertraline, venlafaxine, escitalopram
  • medicines for cancer e.g. doxorubicin, daunorubicin, trastuzumab
  • tramadol (medicine for moderate to severe pain)
  • erythromycin (antibiotic)
  • rifampicin (medicine for TB)
  • ketoconazole (medicine to treat fungal infection)
  • dexamethasone (anti-inflammatory medicine)
This list does not include all medicines that may interact with Ondansetron.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
Avoid alcohol.
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Keep suppositories in their original package to protect from light.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on ondansetron - rectal and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2023 MIMS. All rights reserved. Powered by MIMS.com
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