Alectinib (Alecensa)

Alectinib at a glance

Alectinib, known by the verified brand Alecensa, is a tyrosine kinase inhibitor that targets abnormal ALK signalling. It is taken by mouth, usually twice daily with food. Your team chooses it using your diagnosis and relevant test results, rather than the name of the cancer alone. This guide does not assess Indian brand availability or approval.

Common concerns include constipation, tiredness, muscle discomfort, swelling and skin changes. More serious problems can affect the liver, lungs, kidneys, heartbeat or red blood cells. A rise in blood triglycerides, a type of fat, can occasionally lead to serious inflammation of the pancreas. Blood tests help detect changes that may not cause early symptoms.

Have your treatment plan, current medicine list and urgent hospital number available. Tell the team about side effects when they begin; managing a problem may involve supportive medicines, extra tests or a prescribed treatment interruption. Do not adjust the number of capsules yourself.

How alectinib works

ALK stands for anaplastic lymphoma kinase. It is a protein involved in cell signalling. An abnormal ALK gene arrangement in a cancer can produce an overactive signal that helps cancer cells grow. Alectinib blocks ALK activity, interfering with that growth signal.

Testing determines whether this biological target is present and relevant to your treatment. Alectinib is not interchangeable with every other targeted drug: similar-sounding medicine names may act on different proteins and have different instructions.

Being targeted does not mean it affects only cancer cells or is free of serious side effects. Your team balances expected benefit with the risks and your treatment preferences. Scans, examinations and changes in symptoms help assess progress. Side-effect intensity alone does not show whether the medicine is working.

How your team decides whether it is suitable

Alectinib is used for ALK-positive non-small cell lung cancer, including advanced disease and treatment after surgery in patients at higher risk of recurrence. The assessment includes the exact diagnosis, ALK testing, the extent of disease, previous treatment and your overall health. Ask what test was used and how its result fits the proposed plan. Testing may use tumour tissue or, in some circumstances, blood. A negative blood result does not always settle the question; your clinician may consider tissue testing when appropriate.

Explain any history of liver disease, kidney impairment, slow heartbeat, lung inflammation, muscle disease or anaemia. Also mention high triglycerides, previous pancreatitis and medicines used to control blood fats. These details can affect monitoring and supportive care.

Treatment goals and duration differ between people. Ask what alectinib is intended to achieve in your situation, which appointments assess benefit and what would lead to a change. This discussion should also cover practical issues such as swallowing capsules, arranging meals around doses, travel and reliable access to repeat supplies.

Before your first dose

Your team reviews baseline blood tests and your medicine list. Liver tests and kidney function provide useful starting values. Blood counts help assess anaemia. A triglyceride measurement is recommended before treatment, with repeat measurements during therapy. Pregnancy status should be checked where relevant.

Discuss your normal pulse and blood pressure, especially if you already take heart or blood-pressure medicines. The team may arrange additional heart tests according to your history or symptoms. Tell them about existing muscle pain or weakness so that new changes can be recognised.

Bring every medicine you use, including occasional painkillers, supplements, traditional remedies and topical or non-prescription treatments. Mention any previous allergic reaction. Alecensa contains lactose; a pharmacist should check the product if you have a relevant inherited sugar-intolerance disorder.

Before leaving, confirm your dose in milligrams and the number of capsules per dose, the times you will take them, food instructions, the missed-dose rule and your next blood-test dates. Ask how to obtain urgent advice outside clinic hours and whom to contact if your supply is running low.

Taking alectinib

Dose, food and duration

The usual dose in the reviewed US and European information is 600 mg twice daily with food. With 150 mg capsules, that means four capsules at each dose, not four across the whole day. Your prescribed dose may be different. Severe liver impairment and treatment-related problems can require a lower dose chosen by your clinician.

Take the capsules at consistent morning and evening times agreed with your team. Food is part of the administration instruction because it affects absorption. Do not deliberately take alectinib on an empty stomach or change to a special high-fat diet without advice. If nausea makes eating difficult, ask how to manage meals and dosing.

There is no single treatment length for everyone. Treatment after complete tumour removal is usually planned for up to two years, unless recurrence or side effects require stopping. Treatment for advanced disease continues while beneficial and tolerable. The indication-specific decision belongs to your treating team. Confirm whether your own plan has a planned end date and what follow-up it requires.

Swallowing the capsules

Swallow capsules whole with water. Do not chew, open, crush or dissolve their contents. If swallowing becomes difficult, contact your pharmacist before altering the capsules or improvising a feeding-tube method. Do not use another medicine's dispersion instructions for alectinib.

If you are prescribed a reduced dose, ask the pharmacist to show the new capsule count. Keep the current plan separate from old instructions and mark when the change begins. A family member can help check the record, but one person should confirm each dose has been taken to prevent accidental duplication.

Missed doses and vomiting

The reviewed regional instructions differ. US Alecensa instructions say to skip a missed dose and take the next dose at its regular time. European instructions allow a missed dose to be taken unless the next one is due within six hours. Follow the instructions provided for your own product and treatment plan; ask the pharmacist to clarify any conflict. Never double a dose.

If you vomit after a dose, do not take extra capsules to replace it. Take the next dose at the scheduled time unless your team tells you otherwise. Repeated vomiting or inability to keep fluids down needs prompt advice. If you accidentally take too many capsules, contact your treating hospital immediately and keep the pack available.

Storing and handling treatment

Keep Alecensa in its original container or packaging to protect it from moisture and light. The US product should not be stored above 30°C (86°F); follow the specific storage conditions on your supplied pack. Ask the pharmacist how to protect it during hot weather or travel. Do not leave it in a hot car.

Keep medicines out of children's reach and do not share them. Ask before transferring capsules into a weekly organiser. Return unused supplies through your pharmacy or treatment service rather than leaving them with an old prescription at home.

Monitoring during treatment

Liver blood tests are particularly important early on. The US schedule is every two weeks for the first three months, then monthly and whenever clinically indicated. European information also specifies baseline testing and every two weeks during the first three months, followed by periodic checks. Abnormal results may require more frequent testing. Follow your team's written schedule.

Creatine phosphokinase, called CPK or CK, is an enzyme that can rise when muscles are injured. The labels recommend testing every two weeks during the first month and additional testing when unexplained muscle pain, tenderness or weakness occurs. This is separate from a routine liver test.

Triglycerides should be checked before starting and periodically afterwards. The current US warning does not set one universal repeat interval. Your clinician chooses timing based on your results and risk factors, and may request pancreatic-enzyme tests if levels rise or symptoms suggest pancreatitis.

Other checks include blood counts, kidney function, pulse and blood pressure. Symptom changes may bring tests forward. Keep scheduled cancer assessments even when you feel well; good day-to-day tolerance does not replace scans or other planned reviews.

Common side effects and practical care

Constipation

Alectinib can make bowel movements less frequent or harder to pass. Keep track of your usual pattern and tell the team when it changes. Fluids, suitable fibre and gentle activity may help, but ask what is appropriate if you have a fluid restriction, bowel disease or difficulty eating. A prescribed laxative may be needed.

Do not keep adding fibre or taking laxatives without advice if you have significant abdominal pain, vomiting or a swollen abdomen. Inability to pass stool or wind with these symptoms needs urgent assessment. Some pain medicines and anti-sickness drugs also contribute to constipation, so the whole medicine list should be reviewed.

Tiredness

Fatigue can affect concentration, work and ordinary tasks. Plan rest around activities that matter most and use gentle activity when comfortable. Tell the team if tiredness is new, worsening or interfering with drinking, eating or self-care. Anaemia, a slow pulse, poor sleep and other causes may need assessment rather than simply more rest.

Avoid driving or operating equipment if you feel dizzy, faint, unusually sleepy or unable to concentrate safely. A sudden major change, especially with breathlessness or palpitations, warrants prompt medical advice.

Muscle and joint discomfort

Report unexplained muscle pain, tenderness or weakness, even if it seems similar to exercise soreness. The team may check CPK and decide whether treatment needs to be paused. Do not assume all muscle pain is mild, particularly if you struggle to climb stairs, rise from a chair or perform usual activities.

Ask which pain relief is suitable. Keep a note of when the symptoms began, whether they are worsening and any recent medication change. Severe pain, marked weakness or dark urine needs urgent assessment rather than repeated self-treatment.

Swelling and weight changes

Fluid can collect around the ankles, legs, hands or face. Report new swelling and sudden weight gain. The team will consider treatment effects alongside kidney, heart and other possible causes. Do not start a water tablet or substantially restrict drinking without guidance. Swelling accompanied by breathlessness needs urgent review.

Rash and sensitivity to sunlight

Use gentle skin care and report a persistent or troublesome rash. Alectinib can make skin burn more easily. Avoid prolonged sun exposure during treatment and for at least seven days after the last dose. Use protective clothing, shade, broad-spectrum sunscreen and lip balm with SPF 50 or higher. Continue sensible sun protection afterwards and longer if your team advises it.

Nausea, diarrhoea and taste changes

These can affect eating and drinking. Take prescribed anti-sickness medicine as instructed and ask for help if it is not effective. Report repeated vomiting or increasing loose stools, especially with dizziness or reduced urine. Small, manageable meals may help, while each alectinib dose still needs food. Ask for dietetic advice if intake or weight is falling.

Important problems

Liver injury

Liver tests may change before you feel unwell. Contact the team immediately for yellow skin or eyes, dark urine, unusual bleeding or bruising, persistent nausea, reduced appetite or pain on the right side of the upper abdomen. Do not miss blood tests because you have no symptoms. Severe abnormalities may require a treatment interruption or stopping treatment.

Lung inflammation

New or worsening cough, breathlessness or fever can be caused by inflammation in the lungs, known as pneumonitis or interstitial lung disease. Other causes, including infection, also need consideration. Contact the hospital urgently rather than assuming a change is due to the cancer or lack of fitness. Severe breathing difficulty requires emergency care. Diagnosed interstitial lung disease or pneumonitis requires an immediate treatment interruption and permanent discontinuation if another cause cannot be identified.

Slow heartbeat

Alectinib can slow the pulse, called bradycardia. Dizziness, faintness, unusual weakness or loss of consciousness can be warning symptoms. The team checks your pulse, blood pressure and other medicines that may slow the heart. Do not stop a heart medicine yourself; treatment decisions depend on the cause and severity.

Muscle injury and kidney problems

Severe muscle symptoms and CPK elevations can require treatment to be withheld. Kidney impairment can also occur. Report marked weakness, severe muscle tenderness, reduced urine or new swelling promptly. Dark urine may have several causes, including blood-cell breakdown or liver disease, so it should not be diagnosed at home.

Breakdown of red blood cells

Haemolytic anaemia means red blood cells are being destroyed faster than they can be replaced. It may cause worsening tiredness, breathlessness, dizziness, a racing heartbeat, jaundice or dark urine. Blood tests distinguish it from other causes of anaemia. Suspected haemolysis requires prompt review, withholding treatment and appropriate blood tests. The team decides whether to restart at a lower dose after recovery or stop permanently.

High triglycerides and pancreatitis

Alectinib can increase triglycerides, sometimes substantially. A high level may not produce obvious symptoms, which is why monitoring matters. Severe elevations can be associated with pancreatitis, an inflammation of the pancreas that can be life-threatening. This warning is included in the August 2026 US prescribing information.

Persistent severe upper-abdominal pain, which may spread to the back, particularly with nausea or vomiting, requires urgent medical assessment. Do not wait for the next blood test or assume it is constipation. Severe triglyceride elevation requires the treating team to withhold alectinib and assess pancreatic enzymes and pancreatitis risk. Acute pancreatitis requires withholding treatment until full recovery. Restarting and any dose reduction must be authorised by the treating team. Do not self-adjust alectinib or start lipid-lowering medication based only on a laboratory number.

A hole in the bowel wall

European information reports gastrointestinal perforation, particularly in people with additional risk factors. Severe abdominal pain, a swollen abdomen, fever or vomiting needs urgent assessment. Tell your team about diverticular disease, previous bowel problems and medicines associated with bowel injury before treatment.

Other medicines, supplements and vaccinations

Have all medicines checked, including those prescribed by another clinic. Drugs that slow the heart or lower blood pressure may increase concern about dizziness or bradycardia. Alectinib may also affect levels of some medicines transported by P-glycoprotein or BCRP, including digoxin or dabigatran. This does not mean you should stop them; the pharmacist may arrange monitoring or an alternative.

Some antibiotics, antifungals, seizure medicines, tuberculosis medicines and St John's wort need review. Alectinib and its active breakdown product are considered together when assessing interactions, so instructions for another ALK inhibitor cannot simply be copied. Do not make your own dose reduction or assume that taking medicines hours apart solves an interaction.

Avoid grapefruit, grapefruit juice and Seville oranges in line with Macmillan's patient advice, and tell the pharmacist if these are part of your diet. European information recommends monitoring for relevant interactions. Acid-reducing medicines do not automatically require the restrictions used with some other targeted drugs, but the complete prescription still needs checking.

Ask about flu, COVID-19 and other vaccines. Whether a live vaccine is suitable depends on your immune function and the whole treatment history. Do not adopt a fixed post-treatment waiting period without individual advice.

Everyday life during treatment

A daily routine can make two doses with food easier to manage. Record doses and changes in capsule count. Plan repeat supplies before travel and keep the original packaging and prescription details with you. Ask the pharmacist about crossing time zones rather than bringing two doses too close together.

Balance activity and rest, and ask for support when fatigue or muscle symptoms limit normal tasks. Protect your skin during outdoor activity. If swelling, constipation or nausea affects clothing, sleep or meals, tell the team; these practical effects are legitimate reasons to seek help.

Inform dentists and other healthcare professionals that you take alectinib. Before surgery or a procedure, the oncology and procedural teams should agree any interruption and restart plan. Do not borrow a stopping schedule from a different cancer medicine. Discuss alcohol and dietary advice with your team, particularly if liver tests or triglycerides are abnormal.

Fertility, pregnancy and breastfeeding

Alectinib can harm a developing baby. Pregnancy testing is recommended before treatment for women who can become pregnant. Use effective contraception during treatment and for at least five weeks after the last dose. Men with a partner who can become pregnant should use effective contraception during treatment and for three months afterwards.

European information warns that oral contraceptives may be less effective with alectinib. Ask for a highly effective method or combination of methods suited to you; do not rely on the contraceptive pill without checking. Vomiting or diarrhoea adds another reason to obtain individual advice. Tell the team promptly if you or your partner becomes pregnant during the relevant precaution period.

Do not breastfeed during treatment. US information also advises avoiding breastfeeding for one week after the final dose. European information does not specify a post-treatment interval, so ask for an agreed restart plan rather than assuming feeding can resume immediately.

The effect on human fertility is uncertain. If future parenthood matters to you, discuss preservation options before starting. Contraception is still needed even if you believe fertility has been reduced. Other cancer treatments may require additional or longer precautions.

After treatment stops or changes

Continue the blood tests and symptom follow-up arranged by your team. Keep the contraception and breastfeeding precautions for the specified period, and maintain the sun precautions for at least seven days. New or persistent serious symptoms still need assessment after the final capsule.

A temporary pause should come with clear instructions about repeat tests and restarting. Do not restart from leftover supplies because you feel better or because a blood result looks improved. When treatment ends permanently, update your medicine list and return unused capsules through the recommended route.

Ask what cancer follow-up is planned, which symptoms to report and whether previous adverse effects need longer observation. Keep a record of important reactions and dose changes for future clinicians.

Frequently asked questions