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Trade/other name(s): Caprelsa

Why would this drug be used?

This drug is used to treat advanced medullary thyroid cancer. It is also being studied for use against a number of other cancers.

How does this drug work?

Vandetanib is a type of targeted therapy known as a tyrosine kinase inhibitor. Tyrosine kinases are proteins at the surface of a cell that signal the cell's control center to grow and divide or help form new blood vessels (angiogenesis) to feed the tumor. By blocking these proteins, vandetanib can help stop the growth of cancer cells.

Before taking this medicine

Tell your doctor…

  • If you are allergic to anything, including medicines, dyes, additives, or foods.
  • If you have ever been diagnosed with heart disease, especially long QT syndrome, an abnormal heart rhythm, or congestive heart failure. Vandetanib can change the electrical activity in the heart, which can lead to irregular heartbeats and can be life threatening. People with long QT syndrome should not take this drug. Vandetanib can also weaken the heart muscle, leading to congestive heart failure that in rare cases may be fatal.
  • If you are taking any medicine for your heart.
  • If you have high blood pressure. Vandetanib may raise blood pressure. Your doctor will likely want to monitor this closely during treatment.
  • If you have any type of liver disease (including hepatitis). This drug is cleared from the body mainly by the liver. Reduced liver function might result in more drug than expected staying in the body, which could lead to unwanted side effects. Vandetanib should not be used in people whose liver is not functioning well.
  • If you have any type of kidney disease. Some of this drug is cleared from the body by the kidneys. Reduced kidney function might result in more drug than expected staying in the body, which could lead to unwanted side effects. Your doctor may need to adjust your dose.
  • If you have recently had problems with bleeding or coughing up blood. This drug can increase your risk of bleeding.
  • If you have any problem with low levels of minerals (electrolytes) in the blood, such as calcium, potassium, and magnesium.
  • If you have or have ever had breathing problems.
  • If you have low thyroid hormone levels (hypothyroidism) or are taking thyroid hormone because your thyroid gland has been removed. This drug can lower thyroid hormone levels. Your doctor will check your thyroid function with blood tests before and during treatment.
  • If you are being treated for seizures. Some drugs used to prevent seizures can interact with vandetanib.
  • If you have diarrhea. This drug can cause diarrhea or make it worse. You may be given medicines to help prevent this.
  • If you have any other medical conditions such as diabetes, gout, or infections. These conditions may require that your medicine dose, regimen, or timing be changed.
  • If you have ever had a hole or tear (perforation) in your stomach or intestine, or if you have ever had a fistula (abnormal connection between 2 parts of the intestine)
  • If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug may cause problems with the fetus if taken at the time of conception or during pregnancy (see “Precautions” below).
  • If you are breast-feeding. While no studies have been done, this drug may pass into breast milk and affect the baby. Breast-feeding is not recommended during treatment with this drug.
  • If you think you might want to have children in the future. This drug may affect fertility. Talk with your doctor about the possible risk with this drug and the options that may preserve your ability to have children.
  • About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

Vandetanib can interact with a number of drugs and supplements, so it is important to check with your health care team before taking any new medicines.

The following drugs and supplements can lower the levels of vandetanib in the blood and may make it less effective:

  • Anti-seizure drugs, such as carbamazepine (Tegretol), phenobarbital (Luminal), and phenytoin (Dilantin)
  • Drugs to treat tuberculosis (TB), such as rifampin (Rifadin, Rimactane; also in Rifamate and Rifater) and rifabutin (Mycobutin)
  • The steroid drug dexamethasone (Decadron)
  • St. John's wort (herbal dietary supplement)

If you need to take these drugs, your doctor may need to adjust your dose of vandetanib. Do not start or stop taking these medicines while on vandetanib without talking with the prescribing doctor(s) about all of the medicines you take, including vandetanib.

If vandetanib and certain heart rhythm drugs are taken together there is an increased risk of a serious abnormal heart rhythm that could lead to death. These drugs include amiodarone (Cordarone), disopyramide (Norpace), dofetilide (Tikosyn), flecainide (Tambocor), mexiletine (Mexitil), moricizine (Ethmozine), procainamide (Procanbid, Pronestyl), propafenone (Rythmol), quinidine (Quinidex), sotalol (Betapace, Betapace AF), and tocainide (Tonocard). Vandetanib should be used with caution, if at all, with these drugs.

Other drugs may increase the risk of abnormal heart rhythms when used with vandetanib. These aren’t heart drugs but they do slow the heart’s electrical impulses (prolong the QT interval). They include chloroquine (Aralen), clarithromycin (Biaxin), dolasetron (Anzemet), granisetron (Kytril), haloperidol (Haldol), methadone (Dolophine, Methadose), moxifloxacin (Avelox), and pimozide (Orap).

Any drugs or supplements that interfere with blood clotting may raise the risk of bleeding during treatment with vandetanib, so talk to your doctor before you use them. These include:

  • Vitamin E
  • Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn), and many others
  • Warfarin (Coumadin)
  • Ticlopidine (Ticlid)
  • Clopidogrel (Plavix)
  • Dabigatran (Pradaxa)
  • Rivaroxaban (Xarelto)
  • Apixaban (Eliquis)
  • Any type of heparin injections

Note that many cold, flu, fever, pain, and headache remedies contain aspirin or ibuprofen. Ask your doctor or pharmacist if you aren't sure what's in the medicines you take.

Check with your doctor, nurse, or pharmacist about any other medicines, herbs, and supplements you are taking, and whether alcohol can cause problems with this medicine.

Interactions with foods

No interactions between foods and vandetanib are known at this time, but this doesn't necessarily mean that none exist. Check with your doctor, nurse, or pharmacist about whether certain foods or drinks may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Vandetanib is taken daily as tablets. Swallow the tablets whole with water. They can be taken with or without food. Do not chew or crush the tablets. (If you have trouble swallowing the tablets whole, ask your doctor or pharmacist how to take them.)

The recommended starting dose is 300 milligrams (mg) once a day. People with kidney problems may need to start at a smaller dose. The daily dose may need to be adjusted if you have side effects.

Take this drug exactly as directed by your doctor. If you do not understand the instructions, ask your doctor or nurse to explain them to you. Keep the medicine in a tightly closed container away from heat and moisture and out of the reach of children and pets.


Vandetanib may cause a number of side effects, some of which can be serious or even life threatening. Because of this, doctors must get special training before they are allowed to prescribe this drug. Be sure to closely follow your doctor's instructions for taking this drug and to report any new side effects right away. Do not start new medicines without checking with your doctor or pharmacist about all the drugs you’re taking.

This drug may make you feel tired, weak, or cause blurred vision. Use caution before driving or using machines that require attention and alertness.

This drug may interact with a number of other drugs or supplements in the body – see “Interactions” above. Be sure your doctor is aware of all drugs and supplements you are taking. Do not start or stop taking any drug without talking to your doctor about all the drugs you are taking.

Vandetanib may affect the heart's rhythm. It may also weaken the heart muscles, which could lead to congestive heart failure. Tell your doctor if you have ever been diagnosed with heart disease. Your doctor will test your heart rhythm with an EKG before you start treatment and several times during treatment. Report any episodes of chest pain, extreme tiredness, fainting, lightheadedness, shortness of breath, irregular or slow heartbeat, or swelling in the hands or feet to your doctor right away.

Vandetanib may cause high blood pressure or make it worse. Tell your doctor if you have ever had high blood pressure or are taking medicines for it. Your blood pressure should be checked regularly during treatment.

This drug may cause diarrhea. If left unchecked, this could lead to dehydration and chemical imbalances in the body. Your doctor will likely prescribe medicine to help prevent or control this side effect. It is very important that you take this medicine as prescribed. Make sure you get the medicine right away, so that you will have it at home when you need it. Let your doctor know if the medicine does not control the diarrhea.

Vandetanib can make your skin sensitive to sunlight, which can increase your chances of serious sunburn. While taking this drug and for 4 months afterward, you should limit your exposure to the sun by wearing sunscreen and clothes that cover your skin, including your head, arms, and legs when you go outside.

This drug may increase your risk of bleeding. Speak with your doctor before taking any drugs or supplements that might affect your body's ability to stop bleeding, such as aspirin or aspirin-containing medicines, warfarin (Coumadin), or vitamin E. Tell your doctor right away if you have unusual bruising, or bleeding such as nosebleeds, bleeding gums when you brush your teeth, or black, tarry stools.

Your doctor will likely test your blood throughout your treatment, looking for effects of the drug on blood counts or on blood chemistry levels. Based on the test results, you may be given medicines to help treat any effects. Your doctor may also need to reduce or delay your next dose of this drug, or even stop it completely. Be sure to keep all your appointments for lab tests and doctor visits.

This drug can increase your risk of stroke. Tell your doctor right away if you notice numbness or weakness in part of the body or sudden vision changes, confusion, trouble speaking, loss of balance or coordination, or severe headache.

In rare cases, patients have developed severe lung disease during treatment. Tell your doctor right away if you notice any possible symptoms of lung problems, such as shortness of breath or a new cough.

This drug may rarely cause a fast-spreading rash and blistering or peeling of the skin (usually on the hands), sometimes along with swelling or sores in the mouth. This condition, known as Stevens-Johnson syndrome, can be severe or even life-threatening. Tell your doctor or nurse right away if you notice any new rashes, skin redness, fever, blistering or peeling of the skin, or mouth sores or swelling of the face, hands, or the soles of your feet.

Rarely this drug can cause swelling in parts of the brain. This, called reversible posterior leukoencephalopathy syndrome ,can lead to seizures, headache, high blood pressure, confusion or change in mental status, and vision problems. Call your doctor right away if you have any of these symptoms.

Rarely, vandetanib can cause holes (perforations) in the digestive tract, which can be life-threatening. Tell your doctor or nurse right away if you have any severe stomach (abdominal) pain, especially if you also have nausea, vomiting, constipation, fever, or any other symptom.

This drug might harm the fetus if taken at the time of conception or during pregnancy. This drug should only be used during pregnancy if the potential benefits outweigh the possible risk to the fetus. Women who could become pregnant need to use effective birth control during treatment and for 4 months afterward. Check with your doctor about what kinds of birth control can be used with this medicine. Tell your doctor right away if you think you might be pregnant.

Possible side effects

You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them.


  • Diarrhea*
  • Rash
  • Nausea
  • High blood pressure*
  • Headache
  • Feeling tired
  • Loss of appetite
  • Pain in the abdomen
  • Abnormal blood tests suggesting drug may be affecting the thyroid, liver, or pancreas (Your doctor will discuss the importance of this finding, if any.)

Less common

  • Abnormal heart rhythm/prolonged QT interval*
  • Sensitivity to sunlight*
  • Bleeding*
  • Dry or itching skin
  • Vomiting
  • Feeling weak
  • Blurred vision
  • Trouble sleeping
  • Sore throat
  • Upset stomach
  • Cough
  • Weight loss
  • Depression
  • Abnormal blood tests suggesting drug may be affecting the kidneys (Your doctor will discuss the importance of this finding, if any.)


  • Congestive heart failure with symptoms like rapid weight gain, trouble breathing, and swelling of hands or feet, which may get better after the drug is stopped*
  • Severe skin reactions*
  • Stroke*
  • Severe lung disease*
  • Pneumonia
  • Lower level of thyroid hormone causing symptoms of hypothyroidism
  • Inflammation of the pancreas (pancreatitis)
  • Swelling in the brain*
  • Death due to heart failure, stroke, bleeding, infection, severe skin reaction, or lung disease

*See the "Precautions" section for more detailed information.

There are other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 2011.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.

Last Medical Review: 08/27/2013
Last Revised: 08/27/2013