Sunitinib belongs to the group of cancer-fighting medications known as antineoplastics and more specifically to a class of medications called tyrosine kinase inhibitors. These medications are antitumour medications that slow the growth of blood vessels that feed nutrients to cancer cells by disrupting cell communication. By slowing the growth of these blood vessels, sunitinib can help reduce the size of tumours, which is a collection of cancer cells.

Sunitinib is used to treat a cancer of the bowels and stomach called gastrointestinal stromal tumour (GIST) after treatment with imatinib does not work. It is also used to treat kidney cancer that has spread to other parts of the body, called metastatic renal cell carcinoma, and certain cancers of the pancreas called pancreatic neuroendocrine tumours (pNET) that are advanced or cannot be removed with surgery.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of sunitinib to treat GIST or kidney cancer is 50 mg taken by mouth once daily for 4 weeks, followed by 2 weeks of no therapy. This 6-week cycle is then repeated.

To treat pancreatic neuroendocrine tumours the recommended dose is 37.5 mg taken by mouth once daily with no break in treatment.

Daily doses should not be more than 50 mg or less than 25 mg. Sunitinib can be taken with or without food. Do not take sunitinib with grapefruit juice, since this may interact with sunitinib and increase the amount of sunitinib in your blood.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature (between 15°C to 30°C) in its original package and keep it out of the reach of children.

12.5 mg
Each hard gelatin, self-lock capsule with opaque reddish-brown cap and opaque reddish-brown body, imprinted with "RM53" on cap and "RM53" on body in white ink, filled with yellow-to-orange powder, contains sunitinib maleate equivalent to 12.5 mg of sunitinib. Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate, mannitol, and povidone; Capsule shell: iron oxide red, gelatin and titanium dioxide; Imprinting ink: potassium hydroxide, propylene glycol, shellac, and titanium dioxide.

25 mg
Each hard gelatin, self-lock capsule with opaque caramel cap and opaque reddish-brown body, imprinted with "RM54" on cap and "RM54" on body in white ink, filled with yellow-to-orange powder, contains sunitinib maleate equivalent to 25 mg of sunitinib. Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate, mannitol, and povidone; Capsule shell: iron oxide black, iron oxide red, iron oxide yellow, gelatin and titanium dioxide; Imprinting ink: potassium hydroxide, propylene glycol, shellac, and titanium dioxide.

50 mg
Each hard gelatin, self-lock capsule with opaque caramel cap and opaque caramel body, imprinted with "RM56" on cap and "RM56" on body in white ink, filled with yellow-to-orange powder, contains sunitinib maleate equivalent to 50 mg sunitinib. Nonmedicinal ingredients: croscarmellose sodium, magnesium stearate, mannitol, and povidone; Capsule shell: iron oxide black, iron oxide red, iron oxide yellow, gelatin and titanium dioxide; Imprinting ink: potassium hydroxide, propylene glycol, shellac, and titanium dioxide.

Do not use sunitinib if you:

• are allergic to sunitinib or any ingredients of the medication
• are pregnant

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• changes in sensation of taste
• constipation
• diarrhea
• dizziness
• dry mouth
• dry skin
• hair colour change
• headache
• heartburn or indigestion
• loss of appetite
• mouth pain, irritation, or sores
• nausea
• rash or blisters on the palms of hands or soles of feet
• skin colour change (yellow)
• tiredness
• upset stomach
• vomiting
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• bone pain or bone damage in the jaw
• increased blood pressure
• painful skin ulcers
• signs of a blood clot (e.g., sudden chest pain, shortness of breath, sudden leg pain, leg swelling, or leg redness)
• signs of gallbladder inflammation (e.g., abdominal pain, vomiting)
• signs of an infection (e.g., fever, flu-like symptoms, fatigue, weakness)
• signs of heart failure (e.g., feet or ankle swelling, fatigue when doing regular household activities, shortness of breath)
• signs of heart rhythm irregularity (e.g., dizziness, palpitations, fainting, feeling of rapid, pounding heartbeat)
• signs of kidney failure (e.g., decreased urine production, swelling, fatigue, abdominal pain)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• symptoms of low blood sugar (e.g., cold sweat, cool pale skin, headache, fast heartbeat, weakness)
• signs of decreased thyroid function (e.g., dry skin, constipation, weight gain, fatigue)
• signs of increased thyroid function (e.g., weight loss, sweating irritability)
• unexplained bleeding (e.g., nosebleeds, darkened urine, unusual bruising or bleeding)
• unexplained muscle aches or weakness or dark colored urine

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizure
• signs of an artery dissection or aneurysm (e.g., sudden severe pain in the back, chest, or abdomen; coughing up blood; unusual pulsing in chest or abdomen)
• signs of a serious allergic reaction (e.g., swelling of face or throat, hives, or difficulty breathing)
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools; spitting up of blood; vomiting blood or material that looks like coffee grounds)
• signs of fluid build-up between the lungs and wall of the chest (e.g., shortness of breath and chest tightness)
• signs of a heart attack (e.g., chest pain or pressure, pain extending through shoulder and arm, nausea and vomiting, sweating)
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• signs of reversible posterior leukoencephalopathy syndrome (e.g., headache, seizures, tiredness, confusion, vision changes)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
• signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)
• symptoms of damage to the smallest blood vessels, usually in the organs or brain (e.g., fever, tiredness, bruising, swelling, confusion, vision loss, seizures)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication. 

Abnormal heart rhythms: This medication can cause abnormal heart rhythms, which often have no symptoms. Certain medications (e.g., sotalol, quinidine, thioridazine, chlorpromazine, pimozide, moxifloxacin, mefloquine, pentamidine, arsenic trioxide, tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation, and should not be used in combination with sunitinib. You are more at risk for this type of abnormal heart rhythm and its complications if you:

• are female
• are older than 65 years of age
• have a family history of sudden cardiac death
• have a history of heart disease or abnormal heart rhythms
• have a slow heart rate
• have congenital prolongation of the QT interval
• have diabetes
• have had a stroke
• have low potassium, magnesium, or calcium levels
• have nutritional deficiencies

If you have heart disease and abnormal heart rhythms, or are taking certain medications (e.g., verapamil, atazanavir), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Adrenal gland problems: Adrenal glands produce chemical messengers that are responsible for the normal function of the body's organs, including how your body responds to injury or stress. On rare occasions, sunitinib may cause your adrenal gland to function improperly. Your doctor may monitor your adrenal gland condition especially if you have experienced stress such as surgery, injury, or severe infection.

Bleeding: Sunitinib may increase your risk of bleeding. On rare occasions, tumour bleeding has occurred. If you experience signs of bleeding (e.g., nosebleeds, darkened urine or stools), contact your doctor as soon as possible. Your doctor will perform regular blood tests to monitor you while you are taking this medication.

Blood cell counts: This medication may decrease the number of blood cells in your body. Your doctor will perform a blood test regularly to monitor your blood cell count while you are taking sunitinib.

Blood clots: Sunitinib may cause blood clots in the legs (deep vein thrombosis) to form that can move to the lungs (pulmonary embolism), heart (heart attack) or brain (stroke).

If you have a history of clotting you may be at increased risk of experiencing blood clot-related problems such as heart attack, stroke, or clots in the deep veins of your leg. Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, chest pain, blurred vision or difficulty speaking, seek immediate medical attention.

Blood glucose: Sunitinib can cause large decreases in glucose levels in the blood. This can happen even if you do not have diabetes. People with diabetes may find it necessary to monitor their blood sugar more frequently while using this medication. Changes to your medications may become necessary. If you experience symptoms of decreased blood sugar, such as cold sweats, cool, pale skin, headache, rapid heartbeat or unusual weakness, talk to your doctor. If you experience symptoms of dangerously low blood glucose, such as seizures, delirium, or loss of consciousness, this is a medical emergency and requires immediate medical attention.

Gastrointestinal perforation: Rarely, people using sunitinib who have tumours that have spread to the digestive system develop a tear in the lining of the digestive tract. This may be related to the death of cancer cells in the stomach or intestines. If you notice bloody or black and tarry stools, or vomit blood or material that looks like coffee grounds, seek medical help immediately.

High blood pressure: Your doctor may check your blood pressure before starting sunitinib and then ask you to measure your blood pressure regularly while taking sunitinib. Some people taking sunitinib develop very high blood pressure that requires adding blood pressure medications, changing the sunitinib dose, or even stopping the medication for a period of time. Talk to your doctor if you have any concerns.

Heart problems: This medication can decrease heart function, which may lead to heart failure. If you experience symptoms of heart failure such as unusual tiredness, shortness of breath, or swelling of the feet and ankles, contact your doctor.

If you have a history of decreased heart function (i.e., heart arrhythmias, congestive heart failure such as left ventricular dysfunction, heart attack, heart bypass surgery), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Infection: Like other medications used to treat cancer, sunitinib can cause a decrease in the number of blood cells that fight infection (white blood cells). Rarely, pneumonia or sepsis has been reported. These infections can be fatal. If possible, avoid contact with people with contagious infections. Tell your doctor immediately if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.

Jaw problems: On rare occasions, sunitinib may cause severe jaw problems, especially in people who have had invasive dental procedures or are taking bisphosphonates (e.g., alendronate, risedronate). If you experience any pain in the jaw, contact your doctor immediately. Invasive dental procedures should be avoided if possible.

Kidney function: This medication can cause decreased kidney function or kidney failure. If you experience puffy hands, face or feet, high blood pressure, unusual muscle cramping, or darkened urine, this medication may be affecting how well your kidneys are working. If you notice any of these symptoms, contact your doctor as soon as possible.

Liver function: This medication may cause a decrease in liver function. Sunitinib has also been reported to cause liver failure, which has in some cases caused death. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Your doctor may want to test your liver function regularly with blood tests while you are taking this medication. This often allows reduced liver function to be identified before it becomes too severe.

Male contraception: Sunitinib can cause harm to the fetus if the female partner of a man taking sunitinib becomes pregnant. Men should use effective contraception while taking sunitinib.

Muscle problems: On rare occasions, people have had severe muscle problems while taking sunitinib. If you have muscle aches or weakness, or dark-coloured urine, contact your doctor as soon as possible.

Pancreatitis: Sunitinib can cause the pancreas to become inflamed. If you have a history of pancreatitis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Report signs of pancreatitis such as abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, or swollen abdomen to your doctor immediately.

Reversible posterior leukoencephalopathy syndrome (RPLS): This is a rare disease of the brain that may occur when using medications like sunitinib. If you have had a previous episode of RPLS, sunitinib may not be an appropriate medication for you. Make sure your doctor knows you have experienced this before. If you experience signs and symptoms of RPLS, such as headache, seizures, change in awareness or consciousness, or vision changes, contact your doctor immediately.

Seizures: Rarely, there have been cases of people having seizures while taking sunitinib. If you have a history of seizures or seizure disorders, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Thyroid problems: Sunitinib may decrease thyroid hormone levels. If you have symptoms of low thyroid such as dry skin, constipation, weight gain, or fatigue, go see your doctor.

Tumour lysis syndrome: Sunitinib, like many other cancer medications, causes many cancer cells to be suddenly killed when treatment is first started. This can overwhelm the body with waste products from the cells. As a result, the body may not be able to keep up with getting rid of all the waste. When this happens, you may experience nausea, shortness of breath, cloudy urine, or joint pain. This is called tumour lysis syndrome. Your doctor may prescribe some medications to help your body get rid of the waste products. Make sure you understand how to use these medications and report any of these signs or symptoms to your doctor immediately.

Pregnancy: This medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if sunitinib passes into breast milk. If you are breast-feeding and taking this medication, it may affect your baby. You are advised against breast-feeding while taking this medication.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between sunitinib and any of the following:

• acetylsalicylic acid (ASA)
• amiodarone
• androgens (e.g., testosterone)
• antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• apalutamide
• aprepitant
• "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
• bevacizumab
• bismuth subsalicylate
• bisphosphonates (e.g., alendronate, clodronate, risedronate, zoledronic acid)
• bosentan
• bromocriptine
• calcium channel blockers (e.g., diltiazem, verapamil)
• other cancer medications (e.g., carboplatin, cyclophosphamide, doxorubicin, ifosfamide, vincristine)
• capecitabine
• carbamazepine
• clomipramine
• cobicistat
• conivaptan
• corticosteroids (e.g., dexamethasone, hydrocortisone, prednisone)
• danazol
• diabetes medications (e.g., acarbose, canagliflozin, gliclazide, insulin, liraglutide, metformin, sitagliptin)
• disopyramide
• domperidone
• doxepin
• dronedarone
• enzalutamide
• flecainide
• grapefruit juice
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, etravirine)
• HIV protease inhibitors (e.g., atazanavir, darunavir, lopinavir, ritonavir)
• hydroxychloroquine
• imipramine
• inotuzumab
• letermovir
• linezolid
• lumacaftor and ivacaftor
• macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
• methadone
• mifepristone
• modafinil
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, rasagiline, selegiline, tranylcypromine)
• nirmatrelvir and ritonavir
• pegvisomant
• pentamidine
• phenobarbital
• phenytoin
• primidone
• other protein kinase inhibitors (e.g., crizotinib, dabrafenib, imatinib, nilotinib)
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin)
• rifabutin
• rifampin
• St. John's wort
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline, vortioxetine)
• serotonin antagonists (anti-emetic medications; e.g., granisetron, ondansetron)
• sotalol
• somatostatin analogues (e.g., lanreotide, octreotide, pasireotide)
• sulfonamide antibiotics ("sulfas"; e.g., sulfadiazine, sulfamethoxazole)
• tramadol

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.