Dacomitinib (Vizimpro)

Dacomitinib at a glance

The verified brand is Vizimpro. Dacomitinib belongs to a group of targeted medicines called tyrosine kinase inhibitors, often shortened to TKIs. It interferes with growth signals inside cells, including signals involving the epidermal growth factor receptor, or EGFR. The exact EGFR change in your cancer matters when selecting treatment.

The tablets come in 15 mg, 30 mg and 45 mg strengths. The usual labelled adult starting dose is 45 mg once daily, although the specialist may prescribe a different dose for your circumstances. You can take the tablet with or without food.

Diarrhoea, rash, dry skin, sore nails and mouth soreness are important day-to-day concerns. Early treatment can prevent a manageable problem from becoming serious. Having treatment at home still requires blood tests, clinical reviews and access to urgent advice.

What dacomitinib is and how it works

EGFR is part of a signalling system that helps regulate cell growth. Certain changes in the EGFR gene can keep growth signals active. Dacomitinib blocks the activity of EGFR and related proteins, including HER2 and HER4, within this system. This can slow or interrupt growth in a cancer that depends on an appropriate target.

It is a small-molecule targeted medicine, rather than a checkpoint immunotherapy such as pembrolizumab. Medicines can share a broad name such as “targeted therapy” while having different targets, uses and precautions. A tablet used by another patient cannot be substituted for yours.

Healthy tissues also use these signals. Effects on skin, nails and the lining of the digestive tract help explain some of the side effects. Targeted treatment is not free of risk, and side effects do not reliably tell you whether the medicine is controlling the cancer. The team assesses benefit through symptoms, examinations and planned scans.

How the team decides whether it is suitable

The team reviews the diagnosis, the precise tumour mutation, previous treatments, other health conditions and the medicines you already take. Ask for an explanation of the test result in ordinary language and how it supports the proposed plan.

The important finding is an appropriate activating EGFR mutation, not simply the presence of EGFR protein. The US prescribing information specifically identifies exon 19 deletions and exon 21 L858R substitutions; the European wording refers to activating EGFR mutations. These descriptions require specialist interpretation. Not every EGFR change predicts the same response. A tumour result does not automatically mean that a gene change is inherited.

Tell the team about previous lung inflammation or interstitial lung disease, kidney problems, liver disease, severe diarrhoea, eye problems, skin conditions and previous drug allergies. Experience in people with pre-existing interstitial lung disease is limited. Dacomitinib has not been established as safe and effective for children; adult dosing must not be applied to a child.

Tablets contain lactose. Tell the pharmacist before starting if you have an inherited sugar-intolerance disorder: European information says people with rare hereditary galactose intolerance, total lactase deficiency or glucose-galactose malabsorption must not take this product. These are not the same as milk-protein allergy.

Before treatment starts

The team usually arranges blood tests to check blood counts, liver and kidney function and other substances in the blood. Baseline weight, appetite, bowel pattern and skin symptoms help them recognise changes later. A pregnancy test is required when pregnancy is possible. Additional assessments depend on your history.

Bring a complete list of prescription medicines, occasional remedies, supplements and herbal products. Include medicines for acidity or heartburn, cough mixtures, psychiatric medicines and treatments supplied by another hospital. Acid-reducing medicines need particular attention before the first tablet.

Ask for an anti-diarrhoea medicine and a written plan before starting. You should know when to begin it, the maximum prescribed amount and when to call. Also ask which moisturiser and sun protection to use and whether a preventive skin treatment has been prescribed. Do not wait until a weekend problem develops to find the emergency number.

Save the cancer unit's daytime and after-hours numbers. A short symptom record can include the dose taken, bowel movements, vomiting, food and fluid intake, rash and temperature when unwell. It should support a conversation with the team, rather than make you responsible for judging the medical severity yourself.

How to take dacomitinib

Daily tablets

Take the prescribed dose once a day at roughly the same time. Swallow the tablet whole with water. Food is optional, so choose a routine you can follow consistently. Do not crush, chew or dissolve the tablet without a pharmacist-approved plan. If swallowing is difficult, ask before altering the medicine.

The usual adult starting dose is 45 mg daily. Labelled reductions include 30 mg and then 15 mg daily when required for side effects. These are decisions for the treating team. A dose reduction is a way to manage treatment safely; it does not by itself show that treatment has stopped working.

Severe liver disease illustrates why personal instructions matter. The US label does not recommend a liver-based dose adjustment, while European information recommends a lower starting dose in severe liver impairment, with possible later adjustment. Severe kidney impairment and dialysis also need individual assessment because dosing evidence is limited. Do not choose a dose from an online regional comparison.

Missed dose, vomiting or an extra tablet

If you miss a dose, leave it out and take the next dose at the usual scheduled time. Do not take a catch-up or double dose. If you vomit after a dose, do not replace it; take the next scheduled dose normally unless the team has told you to pause treatment. Report repeated vomiting or difficulty keeping fluids down.

If you take too much, obtain urgent medical advice or go to hospital immediately. Take the packaging and a record of the amount and time if possible. Do not wait for symptoms to appear.

Pauses and supplies

The team may temporarily stop treatment for diarrhoea, skin toxicity, abnormal tests or other concerns. Some problems require permanent discontinuation. Ask for written restart instructions after a pause; feeling better alone is not a restart instruction. Keep old strengths separate after a prescription change and ask the pharmacist what to return.

Monitoring during treatment

At reviews, the team checks how you are managing the tablets, skin and nail changes, bowel symptoms, appetite, weight, breathing and daily activities. Report symptoms between visits when they occur. A reassuring blood test does not rule out a lung problem or severe skin reaction.

Blood tests monitor liver and kidney function and blood counts. Blood salts such as potassium may need checking, especially with diarrhoea or reduced intake. European prescribing information recommends periodic liver-function testing. Your schedule depends on symptoms and previous results; there is no single fixed interval suitable for everyone.

Scans and other disease assessments are arranged according to the treatment plan. Ask when the first response assessment is expected and who will discuss it with you. Taking tablets correctly is important, but neither a rash nor the absence of side effects is a substitute for these assessments.

Common side effects and practical care

Diarrhoea

Loose or more frequent stools are common and can start early. Dacomitinib-related diarrhoea can become severe, causing dehydration, low potassium and kidney injury. Contact the team at the first signs and begin the anti-diarrhoea medicine according to your supplied instructions. Early management is especially important in the first two weeks.

Drink regularly according to your individual fluid plan. If you have heart or kidney disease, ask how much is appropriate rather than forcing large volumes. Record bowel frequency compared with your usual pattern. A stoma producing more liquid than usual also needs attention. Do not rely on dietary changes alone when symptoms persist.

Call urgently if diarrhoea occurs at night, is frequent or worsening, or is not controlled by the prescribed medicine within 24 hours. Call sooner for dizziness, very little urine, inability to drink, severe abdominal pain, blood in the stool or fever. You may need tests, fluids through a drip and a treatment pause.

Rash, dryness and itching

An acne-like rash often affects the face or upper body. It is related to treatment and should not automatically be managed with ordinary acne products, which may irritate it. Tell the team early, even if the rash initially seems mild. Prescribed creams or antibiotics may be needed.

Use a gentle cleanser and unperfumed moisturiser. Limit sun exposure and use protective clothing and sunscreen; Macmillan advises at least SPF 30. Avoid scrubbing or using harsh, alcohol-containing skin products. Do not apply steroid or antibiotic creams without instructions about the correct product and area.

Nails, hands and feet

Skin around the nails may become tender, swollen or infected. Nails can become brittle or change shape. Report painful swelling, discharge or spreading redness promptly. Hands and feet may also develop soreness, cracks or peeling. Tell the team if walking, dressing or handling objects becomes difficult. Protective footwear and avoiding friction can help, but broken or infected skin needs assessment.

Mouth, taste and appetite

Mouth soreness, ulcers and altered taste can make eating difficult. Use a soft toothbrush and follow the team's advice on mouth rinses. Choose foods you can manage comfortably and avoid products that sting. Report white patches, significant pain or difficulty eating and drinking promptly; pain relief, infection treatment or dietitian support may be needed.

Nausea, reduced appetite and weight loss also occur. Small manageable meals may be easier than large portions. Tell the team if intake remains poor or weight is falling. Do not start supplements marketed as cancer treatments without checking their ingredients and interactions.

Tiredness and hair changes

Fatigue may affect work and daily activities. Balance rest with activity that feels manageable, and report a marked or sudden change. Hair may thin, and body-hair growth can change. These effects can be upsetting even when they are not medically dangerous; support and practical advice are appropriate.

Important side effects that need assessment

Lung inflammation

Dacomitinib can cause interstitial lung disease, also called pneumonitis, which can be fatal. New or worsening breathlessness, cough or fever must be assessed urgently. These symptoms can resemble infection or cancer symptoms, so do not assume the cause. Treatment should be withheld while suspected lung inflammation is investigated. Confirmed interstitial lung disease requires permanent discontinuation.

Serious skin problems

A spreading painful rash, marked peeling, extensive cracking or signs of infection needs urgent advice. Blistering with mouth or eye involvement or feeling very unwell requires emergency assessment. The team may interrupt treatment and prescribe additional care. Do not continue through severe skin symptoms just to avoid missing tablets.

Liver problems

Blood tests may show raised liver enzymes before you notice symptoms. Serious liver injury has also been reported. Contact the team immediately for yellow eyes or skin, unusually dark urine, pale stools or other concerning new symptoms. Severe liver-test changes may require a treatment pause and investigation.

Eye problems

Dryness or redness may be manageable with prescribed treatment, but painful eyes, light sensitivity or changed vision needs prompt assessment. Inflammation of the cornea, the clear front surface of the eye, can occur. Do not use leftover steroid eye drops, and do not drive with impaired vision.

Cancer itself and some treatments can also increase the risk of blood clots. A newly swollen painful limb needs urgent advice; sudden chest pain or severe breathlessness needs emergency care. This is general cancer safety advice, not a statement that every such event is caused by dacomitinib.

Other medicines, supplements and vaccinations

Heartburn and acidity medicines

Proton pump inhibitors, such as omeprazole, can reduce dacomitinib absorption and should be avoided with it. Ask the prescriber to arrange an alternative when needed. Do not assume taking the two medicines a few hours apart solves this interaction.

An H2 blocker may be used with carefully planned timing. The US label says to take dacomitinib at least six hours before or ten hours after the H2 blocker. European information uses at least two hours before or ten hours after. Ask the pharmacist to write the schedule for your supplied medicine; do not combine different regional instructions. Locally acting antacids may be another option.

Medicines affected by CYP2D6

Dacomitinib can alter the handling of medicines processed through an enzyme called CYP2D6, sometimes increasing toxicity or changing the amount of an active metabolite. Certain medicines require avoidance or adjustment. The European leaflet specifically names procainamide, pimozide and thioridazine. This is not a complete interaction list. Have all regular and occasional medicines checked, including cough remedies.

Ask before starting any herbal mixture, concentrated supplement or medicine from another clinician. Also tell a dentist or emergency doctor that you take dacomitinib. Do not independently stop an essential medicine; arrange a safe replacement or dosing plan with the relevant prescribers.

Vaccination advice depends on your immune function and other treatments. Discuss flu, COVID-19 and other appropriate vaccines with the team. Live vaccines may be unsuitable when immunity is weakened. A blanket waiting period for every vaccine should not be assumed from the fact that this is a cancer tablet.

Everyday life, storage and practical support

Many people continue selected everyday activities while taking dacomitinib, but symptoms can fluctuate. Plan access to a toilet and drinking water, and allow flexibility around appointments. Ask for support with work, caring responsibilities or transport if side effects interfere.

Do not drive or use machinery when tiredness, eye irritation or changed vision affects your ability to do so safely. Discuss persistent symptoms rather than simply adapting around them. Keep emergency contact details with you when travelling.

Keep tablets in their labelled original packaging, away from children and pets. Follow the pack's storage instructions: the US information specifies controlled room temperature, while European information does not require special storage conditions. Avoid leaving medicine in a hot vehicle or exposing it to moisture. Ask a pharmacist about damaged packaging or unusual storage exposure.

Wash your hands after handling tablets. Other people should avoid direct contact where possible. Return unused tablets to the dispensing pharmacy when advised; do not share them or put them into household wastewater. If supplies are running low, contact the pharmacy early rather than rationing doses.

Fertility, pregnancy and breastfeeding

Dacomitinib can harm a developing baby. If you can become pregnant, use effective contraception throughout treatment and for at least 17 days after the final dose. Discuss which method suits you, including what to do if vomiting or diarrhoea may affect an oral contraceptive. Contact the team immediately if pregnancy is suspected.

The reviewed labels do not provide a separate fixed post-treatment contraception interval for male patients. Ask for advice based on your complete treatment plan and your partner's circumstances rather than borrowing a rule from another TKI. If another medicine requires a longer precaution, the whole plan needs to account for it.

Do not breastfeed during treatment. The US label also specifies at least 17 days after the last dose; European information prohibits breastfeeding during treatment without giving the same fixed post-treatment interval. Agree a safe restart date with the team. Expressing and discarding milk does not make it safe to breastfeed during the restricted period.

The effects on human fertility are not well defined; dedicated fertility studies have not been performed. If future parenthood matters to you, ask about fertility preservation before treatment when feasible. Uncertain fertility effects are not a reason to omit contraception.

After treatment stops

Confirm why treatment is stopping, which symptoms still need monitoring and when your next review is due. Continue the agreed contraception and breastfeeding precautions. Do not restart remaining tablets after a gap without permission, even if your symptoms have improved.

Skin, nail and digestive problems may take time to settle. Report persistent symptoms, and keep follow-up blood tests and scans. New or worsening breathing symptoms still deserve urgent assessment after treatment ends. If a new treatment is starting, ask which supportive medicines to continue and which to return.

Frequently asked questions