Crizotinib (Xalkori)

Crizotinib at a glance

Crizotinib, verified under the brand Xalkori, belongs to a group called tyrosine kinase inhibitors, or TKIs. It blocks certain signals that can drive cancer growth. Tests for changes involving ALK or ROS1 can help the specialist decide whether it is appropriate. The relevant test depends on the diagnosis.

Treatment is usually taken twice daily, with or without food. The dose and formulation depend on the treatment plan, age, body size and organ function. A child's prescription must not be worked out by simply reducing an adult dose.

Common difficulties include sickness, diarrhoea or constipation, tiredness, swelling and visual disturbances. Important risks include liver injury, lung inflammation, heart rhythm changes and serious loss of vision. Blood tests and symptom reviews remain necessary even when you feel well.

Record the formulation, strength and dose times. Agree how caregivers will record doses to avoid omissions or duplication.

How crizotinib works

Some cancer cells depend on abnormal signalling proteins to keep growing. Crizotinib blocks the activity of several proteins, including ALK, ROS1 and MET. ALK and ROS1 changes can involve genes joining in an abnormal way, producing a signal that remains switched on. Blocking a relevant signal can slow or stop growth.

“Targeted” does not mean that only cancer cells are affected. Healthy tissues can also be affected, which explains why a medicine taken at home still needs specialist supervision. Side effects do not prove that treatment is working, and feeling well does not prove that it has stopped working. The team assesses benefit through planned examinations, tests and scans.

How your team decides whether it is suitable

Your specialist checks the diagnosis and any relevant ALK or ROS1 results using an appropriate laboratory method. Ask which finding supports your prescription and whether further testing is needed. This guide does not replace the interpretation of a pathology or molecular report.

Tell the team about previous lung inflammation, liver or kidney disease, slow or irregular heartbeat, fainting, heart failure, sight problems and significant bowel disease. Mention all earlier cancer treatments and any recent unexplained breathing or digestive symptoms. These details may change monitoring or the treatment choice.

Children need a dedicated paediatric plan. Prescribing information covers selected uses from one year of age, but that is not permission to use crizotinib for every childhood cancer. Some young-adult regimens also use body-size dosing and additional supportive care. The specialist must identify the correct schedule rather than relying on age alone.

For pellets or granules, mention rare inherited problems with certain sugars, such as hereditary fructose intolerance. The European granule formulation contains sucrose and has specific restrictions for these conditions. Ordinary food preferences and medically diagnosed sugar-processing disorders are not the same thing.

Before treatment starts

Baseline assessment includes blood counts, liver and kidney function and blood salts. The team reviews heart rate, blood pressure and medicines that could affect the heart. An ECG records the heart's electrical activity; electrolyte measurements help identify factors that increase rhythm risk. European information recommends these checks close to the first dose, with continued monitoring tailored to risk.

Pregnancy testing is needed when relevant. Discuss contraception and fertility preservation before starting. Bring all medicines, vitamins and herbal products to the pharmacist's review.

Eye assessment and support for younger patients

Children on the relevant regimens need an eye examination before treatment, another within one month and then generally every three months. US guidance also applies this schedule to the specified young-adult regimen. New symptoms need assessment between planned appointments. A child may not be able to describe blurred vision or missing parts of their visual field clearly.

For the paediatric and relevant young-adult regimens, anti-sickness medicines are recommended before and during treatment. The team should explain when to give them and how to respond to vomiting or diarrhoea. Some patients need additional hydration, electrolyte replacement or nutritional support. Do not select an anti-sickness medicine independently because interactions and heart-rhythm effects matter.

Ask for written instructions covering the dose, formulation, monitoring dates and contact arrangements outside clinic hours. For a child, include all caregivers who may give treatment.

How to take crizotinib

Dose and daily timing

A common adult schedule is 250 mg twice daily. Selected paediatric and young-adult schedules are calculated using body surface area, a measurement derived from height and weight; the labelled target is 280 mg per square metre twice daily, rounded according to the prescribed dose bands. These figures explain why prescriptions differ and are not instructions for calculating your own dose.

Dose reductions, once-daily schedules or treatment pauses may be needed because of side effects, liver or kidney impairment, or interacting medicines. Follow the latest written prescription. If the directions on a new box differ from the treatment plan, resolve the discrepancy before taking it.

Take doses at consistent morning and evening times, with or without food. Avoid grapefruit, grapefruit juice and products containing grapefruit extract. Taking the medicine with a meal does not make this interaction safe.

Ordinary capsules

The 200 mg and 250 mg ordinary capsules must be swallowed whole with water. Do not crush, chew, split or open them to copy the pellet method. If swallowing is difficult, ask the team about an appropriate formulation.

Oral pellets or granules

Xalkori oral pellets, called granules in European information, come in 20 mg, 50 mg and 150 mg strengths inside shells for opening. Do not swallow these shells. Pellets are used for suitable body-size doses and can also be prescribed under US instructions for an adult who cannot swallow ordinary capsules. Switching requires a new, checked prescription.

Have the pharmacist demonstrate the supplied instructions. Check the number and strength of shells for the whole dose. Open them carefully and pour all the pellets directly into the mouth, or first into a dry spoon or medicine cup and then into the mouth. Follow immediately with enough water to swallow every pellet. If necessary, give the dose in smaller portions followed by water until the whole prescribed amount has been taken.

Do not chew or crush the pellets, sprinkle them on food or improvise a liquid mixture. Other food or drink can follow once they have been swallowed, apart from grapefruit products. The US instructions specify no more than four pellet shells for one dose. Ask for clarification if your written directions seem inconsistent with the supplied instructions.

If pellets are spilled, spat out or only partly swallowed, contact the pharmacist for advice rather than estimating a replacement. Feeding-tube administration needs specialist advice; these oral instructions do not establish a tube method.

Missed doses, vomiting and storage

Take a missed dose when remembered unless the next dose is due within six hours, in which case skip it. Never double a dose. European leaflets explicitly permit the missed dose when six hours or more remain; because wording differs at the exact boundary, follow your own leaflet or pharmacist's advice.

If you vomit after a dose, do not take an extra dose. Take the next dose at its usual time. Report repeated vomiting or difficulty keeping fluids down. If too much medicine is taken, seek advice immediately and have the packaging available.

Keep medicine in its original labelled packaging, out of children's reach. US instructions specify 20–25°C (68–77°F); follow the storage instructions for the product supplied, particularly in hot weather. The pellet instructions allow empty shells to go in household waste; ask the pharmacy how to return unused or expired medicine.

Monitoring and checking whether treatment is working

Liver checks are especially important early on. US information specifies every two weeks for the first two months and then monthly; European information specifies weekly for the first two months and then monthly. More frequent testing may be required if results change. Your team should give you the schedule appropriate to your prescription.

US information specifies blood counts weekly during the first month and at least monthly afterwards. European guidance also specifies weekly checks for the first month and at least monthly afterwards for paediatric treatment; its general warning uses clinically indicated monitoring, intensified for abnormalities, fever or infection. Do not reduce your hospital's testing schedule because another source describes fewer visits.

Pulse and blood pressure are checked regularly. ECGs, blood salts and kidney tests may be repeated, especially with vomiting, diarrhoea, dehydration, interacting medicines or an existing heart condition. US information recommends monthly assessment of visual symptoms for all patients. Formal eye appointments follow the age and regimen plan, with extra assessment for symptoms.

At visits, describe changes in sight, bowel movements, breathing, appetite, energy and swelling. Bring a brief record of missed or vomited doses.

Scans and other response assessments answer a different question from safety blood tests. Ask when benefit will be reassessed, which results will be compared and what would lead to continuing or changing treatment.

Common side effects and practical care

Nausea, vomiting and bowel changes

Use prescribed anti-sickness medicine as directed. Small meals may be easier when appetite is poor. Tell the team if nausea makes you avoid food or if you cannot take essential medicines. Children and some young adults can have particularly troublesome gastrointestinal effects and may need proactive support.

Report diarrhoea early and follow the supplied treatment plan. Record frequency and accompanying pain, blood or fever. Repeated watery stools can lead to dehydration and abnormal blood salts. Ask about a suitable fluid intake; individual heart or kidney problems may affect the advice.

Constipation can also occur. Discuss an appropriate laxative plan rather than alternating treatments without advice. Severe pain, a swollen abdomen, repeated vomiting or inability to pass stool and wind needs urgent assessment rather than routine constipation treatment.

Changes in vision

Blurred vision, flashes, floaters or difficulty with changing light can occur, often early in treatment. Report any new disturbance promptly. Do not dismiss it simply because visual effects are recognised with crizotinib: occasionally sight problems are serious. Stop driving or using machinery while vision is affected.

For children, tell the team about squinting, bumping into objects, difficulty reading or unusual behaviour around light. These observations help decide whether an earlier eye examination is needed.

Swelling, tiredness and nerve symptoms

Swelling around the eyes or in the ankles can occur. Report increasing swelling, rapid weight gain or breathlessness because fluid retention may require investigation. Do not start a water tablet yourself.

Balance rest with gentle activity within your ability. New or disproportionate exhaustion should be assessed for causes such as anaemia, dehydration or liver problems. Tingling, numbness or altered sensation should also be reported, particularly if it affects walking, balance or daily tasks.

Mouth and skin care

Mouth soreness may make eating difficult. Use gentle oral care, a soft toothbrush and the rinses recommended by your team. Report ulcers or pain with swallowing. Seek help early if a child avoids drinking because their mouth hurts.

Skin may become sensitive to sunlight. Avoid prolonged exposure and use protective clothing and sunscreen outdoors. Ask for advice about a new rash, especially if painful, spreading or accompanied by fever.

Important side effects needing prompt assessment

Lung inflammation

Crizotinib can cause serious inflammation in the lungs, called pneumonitis or interstitial lung disease. New or worsening cough, breathlessness or fever requires immediate contact with the treating hospital. Symptoms may resemble infection or the underlying illness, so assessment is needed rather than guessing the cause. Severe breathing difficulty is an emergency. If medicine-related lung inflammation is suspected, withhold further doses while obtaining urgent assessment. Confirmed drug-related pneumonitis requires permanent discontinuation by the treating team.

Liver injury

Yellow skin or eyes, dark urine, pain beneath the right ribs, unusual bruising, marked fatigue or persistent loss of appetite may indicate liver injury. Contact the team immediately. Liver injury may also be found on blood tests before noticeable symptoms appear, which is why scheduled tests cannot be replaced by watching how you feel.

Heart rhythm and pumping problems

Crizotinib can slow the heartbeat and alter electrical recovery between beats, described as QT prolongation. Dizziness, fainting, palpitations or an unusually slow pulse needs prompt assessment; collapse or chest pain needs emergency help. Other medicines and changes in potassium or magnesium can increase the risk.

European information also describes serious heart failure. Report new breathlessness, difficulty breathing when lying down, swelling or rapid weight gain. The team may investigate and change treatment.

Serious eye, blood and abdominal problems

Sudden loss of vision, a marked reduction in sight or loss of part of the visual field needs urgent eye assessment. Use emergency care for sudden major loss of sight. Do not drive yourself. The treating team will decide whether treatment must be withheld or stopped.

Low white blood cells can increase infection risk; low platelets can increase bleeding and low red cells can cause anaemia. Fever, shaking chills or feeling suddenly unwell requires immediate contact. Report unexpected bruising, bleeding or worsening breathlessness.

A hole in the stomach or intestine has been reported. Severe or persistent abdominal pain, a rigid or swollen abdomen, blood in vomit or black stools needs urgent assessment. Kidney problems can also occur; report reduced urine, new swelling or flank pain. Some patients develop kidney cysts that require investigation.

Other medicines, supplements and vaccinations

Crizotinib interacts with medicines affecting an enzyme called CYP3A. Some antibiotics, antifungals, antiviral medicines, seizure treatments and rifampicin can change exposure. St John's wort can reduce its effect. Crizotinib can also raise levels of certain other medicines. Strong CYP3A inhibitors and inducers should be avoided; European guidance also avoids moderate inducers. Unavoidable strong inhibition requires specialist dose management. Every new prescription needs a pharmacist's check.

Medicines that slow the heartbeat or prolong QT require particular attention. These include some heart medicines and some medicines used for nausea or mental health conditions. Do not stop a necessary medicine yourself; the team may choose an alternative, adjust treatment or arrange closer checks.

European information warns that oral contraceptives may be less effective. Ask for a reliable contraception plan rather than relying on the pill alone. Avoid grapefruit and products containing its extract.

Discuss vaccinations with the oncology team. Advice depends on immune function and the complete regimen. Live vaccines may be unsuitable during periods of reduced immunity, while non-live vaccines may be recommended. Travel vaccinations should be discussed before booking.

Everyday life during treatment

Use a dose record that fits your routine. For pellets, prepare the prescribed amount when it is due and check that every caregiver understands the difference between a shell for opening and an ordinary capsule.

Avoid driving, cycling in traffic or operating machinery when vision changes, dizziness or tiredness affect safety. Plan alternative transport for eye appointments or days when symptoms are unpredictable.

Carry the treatment details when travelling or attending another clinic. Arrange enough medicine and identify how blood tests and urgent contact will be maintained. Tell dentists and other clinicians about crizotinib before procedures; the oncology team should advise on any interruption.

Fertility, pregnancy and breastfeeding

Crizotinib can harm an unborn baby. US instructions require effective contraception for patients who could become pregnant during treatment and for 45 days after the final dose. They advise condoms for male patients with partners who could become pregnant during treatment and for 90 days afterwards. European information recommends adequate contraception for both sexes during treatment and for at least 90 days afterwards. Obtain a written plan for your product and circumstances.

Do not rely on oral hormonal contraception alone without specialist advice, because European information warns its effectiveness may be reduced. Contact the team promptly if pregnancy is suspected in you or a partner.

Do not breastfeed during treatment. US information extends this restriction to 45 days after the final dose; European information does not give a fixed post-treatment interval. Confirm a safe restart date with the team rather than assuming feeding can resume immediately.

Fertility may be reduced, and reversibility is uncertain. Discuss sperm, egg or other age-appropriate fertility preservation before treatment where feasible. Missing periods or reduced fertility does not reliably prevent pregnancy.

After treatment stops or changes

Obtain clear instructions for any pause, reduced dose or permanent stop. Do not restart remaining medicine because symptoms have improved. The team may need blood tests or another assessment before deciding whether restarting is safe.

Continue the agreed contraception and breastfeeding precautions. Keep follow-up appointments for unresolved liver, lung, heart, eye or kidney problems and report symptoms that persist or appear after stopping. Tell other clinicians the date of the final dose.

Ask for a written summary of treatment, significant side effects, monitoring still required and the next response assessment. Return unused medicine through the pharmacy's recommended process. If another cancer medicine is starting, confirm which supportive medicines should continue and which instructions have changed.

Frequently asked questions