An antifolate chemotherapy for advanced bowel cancer
Raltitrexed
An antifolate chemotherapy used to treat advanced bowel cancer, given under cancer-team supervision.
What is Raltitrexed?
Raltitrexed is a specialist chemotherapy used to treat advanced bowel (colorectal) cancer, often when the usual fluorouracil-based treatment cannot be used. It is an antifolate that blocks an enzyme called thymidylate synthase, which cancer cells need to make DNA and divide. It is given as an injection into a vein by a cancer team. Its main effects are a fall in blood counts (bone-marrow suppression) and gut side effects such as diarrhoea, nausea and mouth soreness. The dose is reduced in people with kidney problems, as the medicine is cleared by the kidneys. It is a specialist-only treatment with close monitoring.
Education and reference only. This is a plain-language guide to Raltitrexed — 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
Raltitrexed is a chemotherapy medicine of the antifolate type, used to treat advanced bowel (colorectal) cancer. It is often chosen when the standard chemotherapy, fluorouracil, is not suitable, for example because of certain heart problems with that medicine. It is given as an injection into a vein by a specialist cancer team, usually every few weeks. Because the kidneys clear it from the body, the dose is carefully adjusted in people with reduced kidney function. It is a hospital-based, specialist-only medicine that is closely monitored.
How it works
Cancer cells need to make DNA to divide, and one key step relies on an enzyme called thymidylate synthase. Raltitrexed is an antifolate that gets taken up into cells and blocks this enzyme, so cancer cells cannot make the DNA they need and are damaged or killed. Because the medicine builds up inside cells and is then removed by the kidneys, people with poor kidney function clear it more slowly, which is why the dose is reduced in kidney impairment to avoid too much toxicity. Healthy fast-dividing cells in the bone marrow and gut are also affected, which explains its main side effects.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist chemotherapy used in the UK for advanced bowel (colorectal) cancer, often when standard fluorouracil-based treatment is not suitable.
Practical use
How to take Raltitrexed
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given as an injection into a vein by your cancer team, usually every few weeks, not taken at home.
- Have your kidney function and blood counts checked before each dose, as these guide the dose you are given.
- Tell your team straight away about diarrhoea, a sore mouth, or trouble eating and drinking, as these may need treatment or a dose change.
- Contact your team urgently if you get a fever or other signs of infection, as your blood counts may be low.
- Attend all your blood-test and review appointments so the team can monitor for side effects.
Weighing it up
Advantages & disadvantages of Raltitrexed
Advantages
- Offers a treatment option for advanced bowel cancer, including when fluorouracil is not suitable.
- Given as a short injection every few weeks, rather than a long infusion.
- Targets cancer cells by blocking an enzyme they need to make DNA.
Disadvantages
- Lowers blood counts (bone-marrow suppression), raising the risk of infection, bleeding and anaemia.
- Commonly causes gut side effects such as diarrhoea, nausea, vomiting and a sore mouth.
- Needs the dose reduced in kidney problems and must be given by a specialist team with regular blood tests.
Practical use
Good to know
Two things dominate the side-effect picture: a fall in blood counts (bone-marrow suppression), which raises the risk of infection, bleeding and anaemia, and gut toxicity such as diarrhoea, nausea, vomiting and a sore mouth. A crucial safety point is that raltitrexed is cleared by the kidneys, so the dose is reduced in people with kidney problems, and your kidney function is checked before treatment; this lowers the risk of severe, prolonged side effects. Blood counts are checked before each dose, and treatment may be delayed or the dose changed if your counts are low or you have had bad side effects from the previous cycle. Report a fever, severe or watery diarrhoea, or a sore mouth that stops you eating or drinking straight away. It is a specialist medicine given and supervised by a cancer team.
Who should not take it / use with caution
- People who have had a serious allergic reaction to raltitrexed should not receive it.
- It is not used in pregnancy because it can harm an unborn baby; effective contraception is needed during treatment.
- It is used with great care, at a reduced dose, in people with kidney problems, and may be avoided if kidney function is severely reduced.
- It should only be used under a specialist cancer team, with close monitoring of blood counts and kidney function.
Monitoring
- Regular blood tests to check blood counts before each dose.
- Checking kidney function before treatment to set and adjust the dose.
- Reviewing gut side effects, mouth soreness and liver blood tests.
Side effects
- Low blood counts (bone-marrow suppression), raising the risk of infection, bleeding and anaemia.
- Diarrhoea, nausea, vomiting and a sore mouth (mucositis).
- Tiredness, reduced appetite and a temporary rise in liver blood tests.
- Rarely but seriously, severe infections, severe diarrhoea or prolonged low blood counts, which need urgent medical attention.
Key interactions
- It is used carefully alongside other medicines that lower blood counts.
- Medicines and conditions that affect kidney function can change how the body handles it, so kidney function is monitored.
- Tell your team about all your medicines, including over-the-counter ones and supplements, so interactions can be checked.
Available as: A powder made up into a solution given as an injection into a vein by a specialist team.
Answers
Raltitrexed: frequently asked questions
What is raltitrexed used for?
It is a chemotherapy used to treat advanced bowel (colorectal) cancer, often when the usual fluorouracil treatment is not suitable.
Why does my kidney function matter?
Raltitrexed is cleared by the kidneys, so the dose is reduced if your kidney function is low to avoid too much toxicity, and your kidneys are checked before treatment.
What are its main side effects?
The main effects are a fall in blood counts (raising infection, bleeding and anaemia risk) and gut problems such as diarrhoea, nausea and a sore mouth.
How is it given?
It is given as a short injection into a vein by your cancer team, usually every few weeks.
What should I watch for between doses?
Contact your team urgently about a fever or signs of infection, severe diarrhoea, or a sore mouth that stops you eating or drinking, as these can be serious.
Authoritative sources
- BNF
- NICE CKS
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