A targeted tablet for medullary thyroid cancer
Vandetanib
A targeted cancer tablet for medullary thyroid cancer, with important heart-rhythm risks needing close monitoring.
What is Vandetanib?
Vandetanib is a specialist targeted cancer medicine used to treat medullary thyroid cancer, a particular type of thyroid cancer, when it cannot be removed by surgery or has spread. It is a tablet taken by mouth. Its most important risk is that it can seriously disturb the heart's electrical rhythm (prolonging the QT interval), which can lead to a dangerous heart rhythm and, rarely, sudden death; for this reason it is only available through a controlled access programme and needs regular heart tracings (ECGs) and blood-salt checks. It also causes marked photosensitivity and can affect the lungs. It can harm an unborn baby, so effective contraception is essential.
Education and reference only. This is a plain-language guide to Vandetanib — 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
Vandetanib is a targeted cancer medicine known as a tyrosine kinase inhibitor; it blocks signals (including those through RET and VEGFR) that drive cancer growth and blood-vessel formation. It is used to treat medullary thyroid cancer, a particular type of thyroid cancer, when surgery is not possible or the cancer has spread. It is taken by mouth as a tablet. Because of its serious effect on the heart's rhythm, in the UK it is only available through a controlled (restricted) access programme, where prescribers and pharmacies follow specific safety steps. It is prescribed and supervised by a cancer specialist.
How it works
Medullary thyroid cancer is often driven by faulty signals, including through a protein called RET, that tell the cancer to grow. Vandetanib blocks these signals, and also blocks signals (through VEGFR) that the cancer uses to build new blood vessels to feed itself. By switching down both growth and blood-supply signals, it slows the cancer. It is taken every day to keep these signals dampened. Because it can also affect the heart's electrical system, slowing it in a way that lengthens the QT interval, it must be used carefully with regular heart monitoring.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist cancer medicine used in the UK to treat medullary thyroid cancer, available only through a controlled access programme because of its heart-rhythm risks.
Practical use
How to take Vandetanib
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth once a day, at about the same time, as directed through the controlled access programme.
- Keep all your heart-tracing (ECG) and blood-test appointments, as the heart rhythm and blood salts must be checked regularly.
- Give your team a full list of your medicines, as many can add to the heart-rhythm risk.
- Protect yourself from the sun with clothing and high-factor sun cream, as it makes the skin very sensitive to sunlight.
- Use effective contraception during treatment and for the time afterwards your team advises, as it can harm an unborn baby.
Weighing it up
Advantages & disadvantages of Vandetanib
Advantages
- An effective targeted treatment for medullary thyroid cancer that cannot be removed or has spread.
- Taken at home as a daily tablet.
- Used within a controlled programme designed to manage its heart-rhythm risk safely.
Disadvantages
- Can seriously disturb the heart's rhythm, needing regular ECGs and blood-salt checks.
- Only available through a controlled access programme, with extra steps for prescribing and dispensing.
- Causes marked sun sensitivity and can affect the lungs, and can harm an unborn baby.
Practical use
Good to know
The dominant safety issue with vandetanib is its effect on the heart's electrical rhythm: it can prolong what is called the QT interval, which can trigger a dangerous heart rhythm (torsades) and, rarely, sudden death. Because of this, it is only available through a controlled access programme, and you will need regular heart tracings (ECGs) and blood tests to check your blood salts (such as potassium, magnesium and calcium), which are kept in the normal range to lower the risk. Many other medicines also affect the QT interval, so a full medicines list is essential. It causes marked sensitivity to sunlight, so careful sun protection is needed, and it can affect the lungs (causing inflammation) and the skin. Because it can harm an unborn baby, effective contraception is essential during treatment and for a time afterwards. The cancer team monitors closely throughout.
Who should not take it / use with caution
- People who have had a serious allergic reaction to vandetanib should not take it.
- It must not be used by people with certain heart-rhythm problems, including a long QT interval, or alongside some medicines that also affect the heart rhythm.
- It must not be used in pregnancy, as it can harm an unborn baby.
Monitoring
- Regular heart tracings (ECGs) to check the QT interval before and during treatment.
- Blood tests for blood salts such as potassium, magnesium and calcium, kept in the normal range.
- Checking blood pressure, watching for breathing problems, and reviewing the skin for sun-related reactions.
Side effects
- Changes in the heart's electrical rhythm (a prolonged QT interval), which can rarely lead to a dangerous rhythm.
- Marked sensitivity to sunlight, with rashes and other skin reactions.
- Diarrhoea, high blood pressure, headache and tiredness.
- Less commonly but seriously, inflammation of the lungs, which needs urgent attention.
Key interactions
- Many medicines that also affect the heart's QT interval add to the risk, so a full medicines list is essential.
- Some medicines, supplements and grapefruit can change vandetanib levels, so check before starting anything new.
- Things that lower blood salts, such as certain water tablets or severe diarrhoea, increase the heart-rhythm risk and need managing.
Available as: Tablets taken by mouth.
Answers
Vandetanib: frequently asked questions
What is vandetanib used for?
It is a targeted cancer medicine used to treat medullary thyroid cancer when it cannot be removed by surgery or has spread.
Why does it need ECGs and blood tests?
Vandetanib can disturb the heart's electrical rhythm (prolonging the QT interval), so regular heart tracings and blood-salt checks help keep this risk under control.
Why is it only available through a special programme?
Because of its serious heart-rhythm risk, it is provided through a controlled access programme so that prescribing, dispensing and monitoring follow strict safety steps.
Why do I need to avoid the sun?
Vandetanib makes the skin very sensitive to sunlight, so protective clothing and high-factor sun cream are needed to prevent severe reactions.
Can I take it during pregnancy?
No. Vandetanib can harm an unborn baby, so effective contraception is essential during treatment and for the time afterwards your team advises.
Authoritative sources
- BNF
- NICE CKS
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