Ondansetron for sickness | Patient.co.uk If it is nearly time to take your next dose when you remember, skip the missed dose and take your next dose when it is due. You will find a full list in the manufacturer's information leaflet supplied with your medicine. If you are taking tablets or syrup and you are sick within one hour of taking a dose, you should take the same dose again. The way you have been told to take it will depend upon the reason why you are taking it. It is prescribed to stop you from feeling sick. If you are unsure about which is right for you, ask your doctor, nurse, or pharmacist for advice.If you have been prescribed Zofran® Melt or Setofilm® tablets, these tablets dissolve very quickly in your mouth when you put them on the top of your tongue. The table below contains some of the most common ones associated with ondansetron. Take them to your local pharmacy which will dispose of them for you. If you have any questions about this medicine ask your pharmacist. . For these reasons, before you start taking ondansetron it is important that your doctor knows: If you are pregnant or breast-feeding.If you have any problems with the way your liver works.If you have been told you have an irregular heartbeat.If you think you may have a blockage in your bowel, or if you are severely constipated.If you are taking any other medicines. The tablets are quite fragile so you need to peel off the foil packaging rather than try to push the tablet through it. If you are due to have a chemotherapy or radiotherapy treatment that could cause you to feel sick, your doctor will prescribe you a dose of ondansetron an hour or so before the treatment. About ondansetronType of medicine5HT3-receptor antagonist anti-sickness medicineUsed forPrevention or treatment of sickness associated with chemotherapy, radiotherapy or surgeryAlso calledDemorem®; Ondemet®; Setofilm®; Zofran®Available asTablets, orodispersible (melt in the mouth) tablets, oral liquid medicine, suppositories, and injection Ondansetron is known as a 5HT3-receptor antagonist. Serotonin is also referred to as 5HT. Chemotherapy, radiotherapy and surgery may all cause the release of an increased amount of serotonin in your body. Take the container with you, even if it is empty. This medicine is for you. You will then be asked to continue to take ondansetron for up to five more days - tablets are usually prescribed twice daily (every 12 hours), whereas suppositories are prescribed just once daily. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. If you are being prescribed ondansetron because you are due to have an operation, you will be given a dose shortly before the surgery, and then prescribed a couple of doses to take at eight-hourly intervals afterwards. Place the tablet on the top of your tongue and allow it to dissolve before you swallow.If you forget to take a dose, take it as soon as you remember. There are small receptors in your small intestine and brain called 5HT3 receptors. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome. Common ondansetron side-effects - these affect less than 1 in 10 people who take this medicine What can I do if I experience this?HeadacheAsk your doctor to prescribe/recommend a suitable painkillerConstipationTry to eat a well-balanced diet, and drink several glasses of water each