A 5HT3-blocking anti-sickness medicine
Tropisetron
A 5HT3-blocking antiemetic used to prevent nausea and vomiting from chemotherapy, with constipation and headache being common.
What is Tropisetron?
Tropisetron is an anti-sickness (antiemetic) medicine used to prevent the nausea and vomiting that can come with chemotherapy. It belongs to a group called 5HT3-receptor antagonists, which block a signal that triggers sickness. It is usually given to prevent sickness rather than to treat it once it has started. The most common side effects are constipation and headache. It can affect the heart's electrical rhythm (the QT interval), so it is used with care in people with heart-rhythm problems or on other medicines that do the same.
Education and reference only. This is a plain-language guide to Tropisetron — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Tropisetron is an antiemetic, a medicine that prevents nausea and vomiting. It belongs to the 5HT3-receptor antagonist group, the same family used to control sickness caused by chemotherapy. It is mainly used to prevent the nausea and vomiting that certain chemotherapy treatments can cause, and is given before or around treatment rather than waiting for sickness to start. It can be given by mouth or by injection, usually within the cancer-care setting under specialist supervision.
How it works
Chemotherapy can trigger the release of a chemical called serotonin (5HT) in the gut and the part of the brain that controls vomiting. Serotonin acts on receptors known as 5HT3 receptors, which send the signal that makes a person feel sick or vomit. Tropisetron blocks these 5HT3 receptors, interrupting that signal and so preventing nausea and vomiting. Because it works best at stopping sickness before it starts, it is given around the time of chemotherapy as prevention. Blocking these receptors also slows the gut a little, which is why constipation is a common effect.
Company & origin
Originated / developed by: Specialist manufacturer.
An anti-sickness medicine used in the UK to prevent the nausea and vomiting caused by chemotherapy.
Practical use
How to take Tropisetron
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take or receive it as arranged by your cancer-care team, usually before or around chemotherapy to prevent sickness.
- Use it as a preventer as directed, rather than waiting until you feel sick.
- Help manage constipation by keeping up fluids and fibre, and ask about a laxative if needed.
- Tell your team about other medicines, especially any that affect the heart rhythm.
- Report a fast or irregular heartbeat, fainting, or severe constipation to your team.
Weighing it up
Advantages & disadvantages of Tropisetron
Advantages
- Effectively prevents nausea and vomiting caused by chemotherapy.
- Can be given by mouth or by injection to suit the situation.
- Works well in combination with other anti-sickness medicines for stronger treatments.
Disadvantages
- Commonly causes constipation, which may need managing.
- Can cause headache.
- Can affect the heart's electrical rhythm (the QT interval), needing care in some people.
Practical use
Good to know
The most useful thing to know is that tropisetron is mainly a preventer of chemotherapy sickness: it works best when given before sickness starts, and it is often combined with other anti-sickness medicines for the strongest treatments. The most common side effects are constipation and headache; the constipation comes from the medicine slowing the gut, so keeping up fluids and fibre can help. An important safety point is that, like others in its group, it can affect the heart's electrical rhythm (the QT interval), so it is used with care in people who already have heart-rhythm problems, low blood salts, or who take other medicines that affect the QT interval. Tell your team about your other medicines, and report a fast or irregular heartbeat, fainting or severe constipation.
Who should not take it / use with caution
- People who have had a serious allergic reaction to tropisetron or similar 5HT3 antagonists should not take it.
- It is used with caution in people with heart-rhythm problems, a long QT interval, or low blood levels of potassium or magnesium.
- It is used with care, and on specialist advice, in pregnancy and breastfeeding and alongside other medicines that affect the heart rhythm.
Monitoring
- Checking that nausea and vomiting are being prevented during chemotherapy.
- Watching for constipation and managing it where needed.
- Reviewing heart-rhythm risk, including blood salts and other QT-affecting medicines, where appropriate.
Side effects
- Constipation.
- Headache.
- Less commonly, dizziness, tiredness, or changes in the heart's rhythm (the QT interval).
Key interactions
- Other medicines that affect the heart's QT interval should be reviewed when taking tropisetron.
- Low blood levels of potassium or magnesium can add to heart-rhythm risk, so these may be checked.
- Tell your team about all your medicines, as some can change how it is broken down in the body.
Available as: Capsules taken by mouth and a solution for injection.
Answers
Tropisetron: frequently asked questions
What is tropisetron used for?
It is an anti-sickness medicine used to prevent the nausea and vomiting that chemotherapy can cause, by blocking a signal that triggers sickness.
Is it for treating or preventing sickness?
It works best as a preventer, given before or around chemotherapy rather than waiting until sickness has already started.
Why am I constipated?
Constipation is a common side effect because the medicine slows the gut a little; keeping up fluids and fibre, and sometimes a laxative, can help.
Does it affect the heart?
It can affect the heart's electrical rhythm (the QT interval), so it is used with care in people with heart-rhythm problems or on other medicines that do the same.
How is it given?
It can be given by mouth as a capsule or by injection, usually around the time of chemotherapy under specialist care.
The wider class
About 5HT3-receptor antagonist antiemetic
Tropisetron belongs to the 5ht3-receptor antagonist antiemetic class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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