Sunitinib (Sutent)

Medicine at a glance

Sunitinib is a targeted cancer medicine taken as capsules. Sutent is a verified brand; other packs may use the generic name. Treatment can involve planned days off or a continuous daily schedule. Your prescription and treatment calendar determine which applies to you.

Take the correct capsule strength on your treatment days, attend blood and urine tests, and report side effects early. Blood pressure, thyroid function and heart health need particular attention. Taking treatment at home does not remove the need for regular supervision.

What sunitinib is and how it works

Sunitinib blocks several proteins called receptor tyrosine kinases. These proteins transmit signals that can help tumour cells grow and help tumours develop a blood supply. Its targets include VEGF receptors, PDGF receptors and KIT. Blocking several pathways can slow cancer growth; the effect differs between people and diseases.

One part of its action is called anti-angiogenesis: reducing the formation of new blood vessels that support a tumour. Blood-vessel signalling also matters in healthy tissues. This helps explain why treatment can affect blood pressure, bleeding and wound healing. Targeted treatment can therefore cause significant side effects even though it acts on particular signalling pathways.

Sunitinib is not conventional chemotherapy and is not an immune-checkpoint inhibitor. It may be used for different treatment aims. Ask your oncologist what benefit is being sought, how response will be measured and what would lead to a change in treatment.

How the team decides whether it is suitable

The decision considers the exact diagnosis, pathology and relevant molecular findings, earlier treatments, current symptoms and overall health. There is no single universal blood test that establishes suitability for everyone receiving sunitinib. Molecular testing can be important in particular tumour types, but a result must be interpreted in its clinical setting.

The team also reviews blood pressure, recent heart or blood-vessel problems, abnormal heart rhythms, kidney and liver function, thyroid disease, diabetes, bleeding and planned operations. Previous treatment that affected the heart may influence the monitoring plan. Tell the team about a history of aneurysm, which is a weakened and widened area of an artery.

Dose decisions are not based simply on how many capsules another patient takes. Kidney impairment does not automatically require a lower starting dose, including in some patients receiving dialysis, but close supervision remains necessary. Mild or moderate liver impairment may not require a starting change; severe liver impairment has not been adequately studied and European information does not recommend use in that setting.

This guide concerns adult treatment. Safety and effectiveness in children have not been established in the cited product information.

Before treatment starts

Expect a review of your medicines, allergies and medical history, together with baseline blood pressure and laboratory tests. Tests generally include a full blood count, liver and kidney function, thyroid function, blood glucose and a urine check for protein. An ECG records heart rhythm; a heart ultrasound or another heart-function test may be considered before treatment and repeated according to risk.

The mouth and teeth should be assessed. Tell the team about painful or loose teeth, gum infection, dentures causing sores, planned extractions and any previous or current bone-strengthening injections. Dental disease, invasive dental work and bisphosphonates can increase the risk of jaw-bone damage during treatment. Arrange preventive care with the cancer team and dentist together.

Pregnancy testing is required by US prescribing information for people who could become pregnant. Discuss contraception, breastfeeding and fertility before the first dose. Make sure any high blood pressure or thyroid disorder has a management plan. If you use diabetes medicine, ask how glucose will be checked and who will adjust treatment if it falls.

Before leaving the clinic, know the capsule strengths, daily dose, start and stop dates, missed-dose rule, expected tests and your hospital's urgent contact route. Keep these instructions available.

How to take sunitinib

Your dose and calendar

Take sunitinib once daily on your prescribed treatment days. Labelled examples include 50 mg daily for four weeks followed by two weeks off, making a six-week cycle, and 37.5 mg daily without a planned break. These are examples, not interchangeable options or a prescription for you. Treatment may continue while helping and tolerable, or follow a specified course.

Some specialists use modified calendars, such as two weeks taking treatment followed by one week off. Cancer Research UK describes this variation. Only use it if it is your written plan; do not shorten or extend a break yourself. Dose reductions and pauses can help manage toxicity without necessarily meaning that treatment has failed.

Capsules come in 12.5 mg, 25 mg, 37.5 mg and 50 mg strengths in the cited Sutent information. More than one capsule may make up a dose. Check the strength when each supply arrives, especially after a change.

Food, swallowing and practical handling

You can take the capsules with or without food. Use a consistent daily time and swallow them whole with water. Do not chew or open them. If swallowing is difficult or you use a feeding tube, ask the cancer pharmacist for an individual plan; do not make a home-made liquid or put capsule contents down a tube yourself. Avoid grapefruit and grapefruit juice.

Store the medicine in its original labelled pack, safely away from children, excess heat and moisture. Follow the storage instructions supplied with your product. Return unwanted capsules through your hospital or pharmacy rather than putting them into household rubbish or wastewater. Do not share your medicine.

Missed doses, vomiting and accidental extra doses

Get a written missed-dose instruction because regional labels differ. The US Sutent guide says to take a forgotten dose immediately if it is less than 12 hours late; if more than 12 hours late, omit it and take the next scheduled dose normally. It does not specify the exact 12-hour boundary, so ask your pharmacist if this occurs. European information says to omit a missed dose and take the usual dose the following day. Follow the instruction for your supplied product and treatment plan, and never double a dose.

If you vomit after a dose, do not take a replacement capsule; take the next scheduled dose at its usual time. Report repeated vomiting or difficulty retaining fluids. If you take too much, obtain urgent advice from your treatment team or emergency service and have the medicine pack available.

Monitoring and checking whether treatment is working

Monitoring looks for effects you may not feel. European information recommends a full blood count at the start of each cycle. Liver tests are checked before starting, during each cycle and whenever symptoms warrant. Kidney tests and urine protein checks help detect kidney injury or leakage of protein into the urine. Extra blood tests may be needed after diarrhoea, vomiting or an abnormal result.

Blood pressure is checked before and during treatment. If home monitoring is requested, ask for the technique, recording schedule and the readings that require a call. Do not wait for symptoms: high blood pressure often produces none. The team may prescribe or adjust blood-pressure treatment and may temporarily hold or stop sunitinib if necessary.

Thyroid tests are needed at baseline and during treatment; European information specifies routine checks every three months, with earlier testing if symptoms develop. US information recommends periodic testing without imposing that fixed interval. Glucose also needs monitoring, including after stopping under US instructions. Heart scans, ECGs and potassium or magnesium checks are tailored to heart risk and interacting medicines.

Symptoms, examination and scans assess the cancer's response. Report effects on walking, eating and daily activities so the team can help.

Common side effects and practical management

Tiredness, appetite and taste changes

Fatigue can affect concentration, activity and work. Balance rest with manageable movement. Mention a marked change rather than assuming all tiredness is inevitable: anaemia, thyroid changes, low glucose or heart problems can also cause it. Report breathlessness, dizziness or rapid weight gain promptly.

Food may taste different and appetite may fall. Try smaller meals and flavours or textures you tolerate, and ask for dietary support if weight is dropping. Mouth pain and nausea are treatable contributors to poor intake. Seek help before dehydration or substantial weight loss develops.

Diarrhoea, nausea and constipation

Use prescribed anti-sickness or anti-diarrhoea treatment as directed. Replace fluids within any kidney or heart-related fluid limit. Contact the team promptly for repeated watery stools, persistent vomiting, dizziness or reduced urine. Bloody diarrhoea, fever or severe abdominal pain needs urgent assessment, not simply more anti-diarrhoea medicine. Constipation also deserves advice, especially with pain or vomiting.

Mouth soreness

Use gentle oral care and a soft toothbrush. Avoid foods that sting sore areas. Tell the team about ulcers, white patches, painful swallowing or difficulty eating or drinking; mouth infection and treatment-related inflammation need different management. Ask before buying medicated mouthwashes. Persistent jaw pain or a non-healing extraction site should not be dismissed as an ordinary mouth ulcer.

Hands, feet, skin, nails and hair

Hand-foot syndrome can cause sore pressure areas, thickened skin, cracks or blisters on palms and soles. Reduce rubbing and pressure, use comfortable footwear and moisturise regularly. Report pain early, particularly if walking or normal hand use becomes difficult. The team may provide creams, pain relief or a treatment pause.

Skin may become dry or develop a rash; hair may lighten or become thinner. Yellowish skin or urine can reflect the medicine's colour, but do not assume every colour change is harmless. Yellow eyes, dark urine with other symptoms, itching or abdominal pain require a liver check. Report painful nail changes or signs of infection. Protect skin from strong sun.

Blood-count and thyroid changes

Low infection-fighting cells can increase infection risk; low platelets can cause bruising or bleeding, and low red cells can cause anaemia. Report fever, chills, unexplained bruises or unusual bleeding promptly. Serious infection can occur even without a low white count.

An underactive thyroid may cause cold intolerance, constipation, weight gain or slowing down. An overactive thyroid can cause palpitations, sweating or weight loss, and can sometimes precede an underactive phase. Testing distinguishes these possibilities. Thyroid medicine may be needed while cancer treatment continues.

Less common but important side effects

Liver injury

Sunitinib can cause serious and occasionally fatal liver injury. Blood tests may show a problem before symptoms appear. New yellow eyes or skin, dark urine, unusual itching, upper abdominal discomfort or unexplained severe tiredness needs prompt assessment. Severe abnormalities can require permanent discontinuation; do not restart after a liver-related hold without explicit instructions.

Heart, blood pressure and circulation problems

The medicine can weaken heart pumping, affect blood supply to the heart or disturb its electrical rhythm. New ankle swelling, breathlessness or palpitations needs urgent contact. Chest pain, fainting or severe breathing difficulty is an emergency. Clinical heart failure requires permanently stopping under US guidance; less severe test changes may lead to a pause or reduction.

Blood clots can affect legs, lungs or arteries. Report one-sided limb swelling or pain; sudden breathlessness, chest pain or stroke-like symptoms require emergency care. VEGF-pathway medicines can also be associated with arterial aneurysm or dissection. Sudden severe chest, back or abdominal pain must be assessed immediately.

Bleeding and abdominal complications

Bleeding can occur inside the body as well as from the nose or gums. Vomiting blood, black tar-like stools, coughing significant blood or bleeding that will not stop needs emergency assessment. A bowel perforation is a hole in the bowel wall; a fistula is an abnormal connection between tissues. Severe or persistent abdominal pain, swelling, fever or vomiting may signal a serious complication, including pancreatic inflammation.

Kidney injury, small-vessel damage and tumour breakdown

Protein in the urine may cause frothiness or swelling; reduced urine can indicate kidney injury. Thrombotic microangiopathy, or TMA, damages small blood vessels and blood cells and can harm the kidneys. Unusual bruising with profound tiredness, fever, confusion or reduced urine requires urgent evaluation. Confirmed TMA requires stopping treatment. Nephrotic syndrome, a severe protein-leak disorder, also requires stopping.

Tumour lysis syndrome occurs when rapid tumour-cell breakdown disturbs blood salts and kidney function. Risk depends on disease burden and other factors; preventive fluids or medicines are individualised. Reduced urine, severe weakness, muscle cramps, palpitations or confusion needs urgent review. Do not force extra fluids if you have a prescribed fluid restriction.

Severe skin reactions and infections

A spreading painful rash with blisters, peeling or sores around the mouth, eyes or genitals needs urgent hospital assessment. Do not take another dose while urgently seeking advice. Serious reactions such as Stevens-Johnson syndrome or toxic epidermal necrolysis require permanent stopping and must not be treated as simple dry skin.

Rarely, a rapidly spreading deep-tissue infection called necrotising fasciitis occurs, including around the genitals or anus. Severe local pain, swelling, redness or darkening with fever or feeling very unwell is an emergency. Immediate treatment and discontinuation of sunitinib are necessary.

Low glucose and neurological symptoms

Sunitinib can lower blood glucose, including in people without diabetes. Sweating, shaking, hunger, dizziness or confusion may be warning signs. Follow your prescribed low-glucose plan and contact the team; diabetes medicines may need adjustment. European guidance also requires a temporary hold for symptomatic hypoglycaemia. Collapse, seizures or inability to swallow safely requires emergency care. Do not give food or drink to an unconscious person.

Severe headache, vision changes, confusion or seizures can signal a brain condition called posterior reversible encephalopathy syndrome, sometimes termed RPLS. Despite its name, it can be life-threatening. Unexplained drowsiness or altered behaviour can also reflect raised blood ammonia. Both need urgent assessment. The detailed US dose table requires permanently stopping sunitinib for RPLS; European guidance permits a clinician-directed restart after resolution in selected circumstances.

Jaw problems and wound healing

Osteonecrosis means damage and death of bone tissue. Report jaw pain, exposed bone, swelling, loose teeth or a socket that fails to heal. Sunitinib can also delay healing elsewhere. Tell the cancer team about any operation or invasive dental procedure well in advance.

US information advises holding treatment for at least three weeks before elective surgery, then for at least two weeks after major surgery and until the wound has healed adequately. It also advises a hold of at least three weeks before planned dental surgery or invasive dental procedures where possible. European guidance leaves surgical timing to clinical judgement. These are planning rules for your clinicians: get your own stop and restart dates, including for urgent procedures.

Other medicines, supplements and vaccinations

A liver enzyme called CYP3A4 helps process sunitinib. Strong inhibitors can raise exposure and increase toxicity; strong inducers can reduce exposure. Examples needing a check include clarithromycin, certain antifungals, ritonavir-containing medicines, rifampicin, carbamazepine and phenytoin. Avoid St John's wort and grapefruit. The pharmacist may recommend an alternative medicine or a specialist dose change; changing the time of day alone does not solve these interactions.

Medicines that prolong QT, the heart’s electrical reset interval, can add to rhythm risk and require closer ECG monitoring. Blood thinners and antiplatelet drugs require careful bleeding assessment; do not stop prescribed treatment without advice. Diabetes medicines may need reduction if glucose falls. Tell the team about bone-strengthening treatments and all painkillers, herbal products and supplements.

There is no standard sunitinib rule requiring everyone to stop acid-reducing treatment or separate it by a fixed number of hours. Nevertheless, have the exact product checked. Discuss vaccinations with the team, especially when counts are low; live vaccines may be unsuitable during cancer treatment.

Everyday life during treatment

A simple diary can link symptoms, blood-pressure readings and treatment days. Bring it to appointments, especially if symptoms build up near the end of a treatment block. Confirm the next cycle if tests or review are delayed.

Stay active within your limits and protect sore feet from pressure. Avoid driving or machinery if dizzy, unusually tired, confused or affected by low glucose. Seek advice about work or travel when access to urgent care or testing would be difficult.

Keep up dental care and tell any treating professional that you take sunitinib. Ask about alcohol if liver tests are abnormal or you have mouth soreness or dehydration. Financial, emotional and practical problems also deserve discussion; support can make a prolonged oral-treatment course easier to manage.

Fertility, contraception, pregnancy and breastfeeding

Sunitinib can harm a developing baby. US information advises effective contraception during treatment and for at least four weeks after the last dose for someone who could become pregnant. For a male patient with a partner who could become pregnant, the US interval is during treatment and seven weeks afterwards. Report suspected pregnancy promptly.

European information emphasises effective contraception during treatment but does not specify the same post-treatment intervals. Obtain a clear written plan based on your product and circumstances; an absent interval in one leaflet is not permission to stop contraception immediately.

Do not breastfeed during treatment. US information specifies at least four weeks after the final dose; European information does not give a fixed post-treatment interval. Ask your team when breastfeeding can safely resume. Animal findings suggest that fertility in both sexes may be affected. Discuss preservation options before treatment if future parenthood matters to you.

After treatment finishes

Keep the planned follow-up for the cancer and any treatment effects. Blood pressure, thyroid function, blood counts, heart function, kidney or liver tests may need further review according to what happened during treatment. Glucose monitoring after discontinuation is specifically advised in US information, and diabetes treatment may need reassessment.

Do not independently stop medicines started for blood pressure or thyroid problems. Continue contraception and breastfeeding precautions for the agreed period. Tell dentists and surgeons when your last dose was, because wound healing and jaw problems remain relevant. Seek help for new serious symptoms rather than assuming the end of treatment has removed every risk.

Frequently asked questions