Do not take Ondansetron if:

• you are taking apomorphine (used to treat Parkinson’s Disease)
• you are allergic (hypersensitive) to Ondansetron or any of the other ingredients of this medicine (listed in section 6). Signs of an allergic reaction include: a rash, swallowing or breathing problems, swelling of your lips, face, throat or tongue

If you are not sure, talk to your doctor, nurse or pharmacist before taking Ondansetron.

Warnings and precautions

Talk to your doctor or pharmacist before taking Ondansetron if:

• you have ever had heart problems (e.g. congestive heart failure which causes shortness of breath and swollen ankles)
• you have an uneven heart beat (arrhythmias)
• you are allergic to medicines similar to ondansetron, such as granisetron (known as ‘Kytril’)
• you have liver problems
• you have a blockage in your gut or suffer from severe constipation
• you have problems with the levels of salts in your blood, such as potassium, sodium and magnesium
• you are intolerant to some sugars.

If you are not sure if any of the above apply to you, talk to your doctor, nurse or pharmacist before taking Ondansetron.

Children

Do not give this medicine to children under 6 months of age

Other medicines and Ondansetron

Tell your doctor, nurse or pharmacist if you are taking, have recently taken or might take any other medicines. This includes medicines obtained without a prescription and herbal medicines. This is because Ondansetron can affect the way some medicines work. Also some medicines can affect the way Ondansetron works.

In particular, tell your doctor, nurse or pharmacist if you are taking any of the following medicines:

• carbamazepine or phenytoin used to treat epilepsy, as these medicines may reduce the effect of Ondansetron
• rifampicin used to treat infections such as tuberculosis (TB), as this medicine may reduce the effect of Ondansetron
• antibiotics such as erythromycin or ketoconazole
• anti-arrhythmic medicines used to treat an uneven heart beat, as these medicines may interact with Ondansetron & effect the rhythm of the heart
• beta-blocker medicines used to treat certain heart or eye problems, anxiety or prevent migraines, as these medicines may interact with ondansetron and effect the rhythm of the heart
• tramadol, a pain killer, as Ondansetron may reduce the effect of tramadol
• medicines that affect the heart (such as haloperidol or methadone)
• cancer medicines (especially anthracyclines), as these may interact with ondansetron to cause heart arrhythmias
• medicines used to treat depression and/or anxiety:
  • SSRIs (selective serotonin reuptake inhibitors) including fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram, escitalopram
  • SNRIs (serotonin noradrenaline reuptake inhibitors) including venlafaxine, duloxetine.

If you are not sure if any of the above applies to you, talk to your doctor, nurse or pharmacist before having Ondansetron.

Pregnancy, breast-feeding and fertility

Only use Ondansetron during the first trimester of pregnancy after discussion with your doctor of the potential benefits and risks to you and your unborn baby of the different treatment options. This is because Ondansetron can slightly increase the risk of a baby being born with cleft lip and/or cleft palate (openings or splits in the upper lip and/or the roof of the mouth).

If you are already pregnant, think you might be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking Ondansetron.

If you are a woman of childbearing potential you may be advised to use effective contraception.

Do not breast-feed if you are taking Ondansetron. This is because small amounts pass into the mother’s milk. Ask your doctor or midwife for advice.

Driving and using machines

It is not expected that Ondansetron will affect your ability to drive; however, if any of the side effects (listed section 4) affect you (e.g. dizziness, blurred vision) caution is advisable. Do not drive or operate machines if you are feeling unwell.

Ondansetron contains:

Sorbitol (E420): This medicine contains 2100mg sorbitol in each 5ml dose which is equivalent to 420mg/ml. Sorbitol is a source of fructose. If your doctor has told you that you (or your child) have an intolerance to some sugars or if you have been diagnosed with hereditary fructose intolerance (HFI), a rare genetic disorder in which a person cannot break down fructose, talk to your doctor before you (or your child) take or receive this medicine. Sorbitol may cause gastrointestinal discomfort and mild laxative effect.

Sodium benzoate (E211): This medicine contains 6mg sodium benzoate in each 5ml dose which is equivalent to 1.2mg/ml.

Propylene glycol (E1520): This medicine contains 14.1mg/5ml propylene glycol in each 5ml dose which is equivalent to 2.8mg/ml.

Sodium: This medicine contains less than 1 mmol sodium (23 mg) per 5ml dose, that is to say essentially ‘sodium-free’.