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Generic name: vandetanibvan-DET-a-nib ]
Drug classes: EGFR inhibitors, Multikinase inhibitors, VEGF/VEGFR inhibitors

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jun 7, 2022.

What is Caprelsa?

Caprelsa is a cancer medicine that interferes with the growth and spread of cancer cells in the body.

Caprelsa is used in adults to treat thyroid cancer.

Caprelsa is available only from a certified pharmacy under a special program called Caprelsa REMS Program. You must be registered in the program and understand the risks of taking this medicine.


Do not use Caprelsa if you are pregnant. It could harm the unborn baby.

You should not use this medicine if you have severe liver disease, a personal or family history of long QT syndrome, or if you have low blood levels of calcium, potassium, or magnesium.

You will need medical tests every 2 weeks to 3 months.

Call your doctor right away if you have a headache with chest pain and sudden dizziness, fainting, and fast or pounding heartbeats.

There are many other drugs that can interact with vandetanib. Tell your doctor about all medications you use. To be sure Caprelsa is not causing harmful effects, your blood may need to be tested often. Your heart rate may also need to be checked using an electrocardiograph or ECG (sometimes called an EKG).

If you need surgery, tell the surgeon ahead of time that you are using Caprelsa. You may need to stop using the medicine for a short time. Do not stop taking this medication unless your doctor tells you to. If you stop taking Caprelsa for longer than 2 weeks for any reason, do not start taking it again without your doctor's advice.

Before taking this medicine

You should not use Caprelsa if you are allergic to vandetanib, or if you have:

  • long QT syndrome (in you or a family member).

To make sure Caprelsa is safe for you, tell your doctor if you have ever had:

  • heart disease, high blood pressure, or a heart rhythm disorder;

  • low blood levels of calcium, magnesium, or potassium;

  • abnormal thyroid function tests;

  • a seizure;

  • breathing problems, cough with bloody mucus;

  • liver or kidney disease;

  • skin problems; or

  • severe diarrhea.

You may need to have a negative pregnancy test before starting this treatment.

Do not use Caprelsa if you are pregnant. It could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 4 months after your last dose. Tell your doctor right away if you become pregnant.

Do not breastfeed while using this medicine, and for at least 4 months after your last dose.

How should I take Caprelsa?

Take Caprelsa exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Take this medicine with a full glass of water.

Caprelsa is usually taken once per day, with or without food.

Swallow the tablet whole and do not crush or chew it.

If you cannot swallow a tablet whole, place it into a glass with 2 ounces of water. Stir until the tablet is dispersed (it will not dissolve completely). Drink this mixture right away. Add 4 ounces more water to the glass, swirl gently and drink right away.

The dispersed tablet mixture can also be given through a nasogastric (NG) or gastronomy feeding tube. Follow your doctor's instructions.

Do not use a broken tablet. The medicine from a broken pill can be dangerous if it gets in your mouth, eyes, or nose, or on your skin. If this happens, wash your skin with soap and water or rinse your eyes with water. Ask your pharmacist how to safely dispose of a broken pill.

You will need blood tests and an electrocardiograph or ECG (sometimes called an EKG) every 2 weeks to 3 months. Your dose or medication schedule may be changed based on the results.

Do not stop taking Caprelsa unless your doctor tells you to. If you stop for longer than 2 weeks for any reason, do not start taking this medicine again without asking your doctor. You may need an ECG before you start taking the medicine again.

Store at room temperature away from moisture and heat.

Dosing information

Usual Adult Dose for Thyroid Cancer:

Initial dose: 300 mg orally once daily.
Duration of therapy: Continue drug until disease progression or unacceptable toxicity occurs.

Use: For the treatment of symptomatic or progressive medullary thyroid cancer in patients with unresectable locally advanced or metastatic disease.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if your next dose is due in less than 12 hours. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

Avoid taking an herbal supplement containing St. John's wort at the same time you are taking Caprelsa.

Avoid exposure to sunlight or tanning beds. Vandetanib can make you sunburn more easily, for up to 4 months after you stop taking the medicine. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Caprelsa side effects

Get emergency medical help if you have signs of an allergic reaction to Caprelsa (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

You may need to stop taking Caprelsa permanently if you have a severe skin reaction.

Call your doctor at once if you have:

  • fast or pounding heartbeats, fluttering in your chest, sudden dizziness (like you might pass out);

  • wheezing, dry cough, feeling short of breath;

  • severe or ongoing diarrhea;

  • unusual bruising or bleeding;

  • cough with bloody mucus, vomit that looks like coffee grounds;

  • swelling, rapid weight gain;

  • headache, confusion, change in mental status, seizure;

  • thyroid symptoms - extreme tiredness, dry skin, joint pain or stiffness, muscle pain or weakness, hoarse voice, feeling more sensitive to cold temperatures, weight gain; or

  • dangerously high blood pressure - severe headache, pounding in your neck or ears, anxiety, irregular heartbeats.

Stop using Caprelsa and call your doctor at once if you have signs of a stroke:

  • sudden numbness or weakness (especially on one side of the body)

  • confusion, trouble speaking or understanding what is said to you;

  • sudden severe headache; or

  • problems with vision or balance.

Common Caprelsa side effects may include:

  • high blood pressure;

  • diarrhea, stomach cramps, nausea, loss of appetite;

  • headache, tiredness;

  • acne, skin rash; or

  • cold symptoms such as stuffy nose, sneezing, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Caprelsa?

Caprelsa can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

Many drugs can interact with vandetanib. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Caprelsa only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.