Entrectinib is used to treat certain cancer (solid tumour) in various parts of the body that is caused by a change in a gene known as neurotrophic tyrosine receptor kinase (NTRK).
It is also used to treat a type of lung cancer (non-small cell lung cancer) that is caused by a change in a certain gene known as ROS1.
Entrectinib is used for those who have a tumour that has spread to other parts of the body.
Take Entrectinib exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
You may take it with or without food. Swallow the capsule whole with a glass of water. Do not open, crush, chew or dissolve the contents of the capsule. Try to take it at the same time each day.
The dose of this medicine will be decided by your doctor. Your doctor will advise you on the dosage and treatment timeframe depending on your condition and response to the medication.
Entrectinib must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
If you missed a dose and it is within 12 hours of your usual schedule, take the missed dose as soon as you remember and return to your normal dosing schedule.
If you are more than 12 hours late, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Alert your doctor if you have congenital QT syndrome (an inherited disease causing abnormally fast heartbeats) as Entrectinib may not be suitable for you.
Do not take this medicine if you are pregnant. If you become pregnant while on Entrectinib therapy, alert your doctor immediately. This medicine may cause harm to your unborn child.
It is important that you do not get pregnant while taking this medicine. You must use proven birth control methods during Entrectinib therapy and for 5 weeks after stopping the treatment. Male patients must also use proven birth control methods while taking this medicine if their partner is of childbearing potential. Adequate contraceptive methods must be used during therapy and 3 months after stopping the treatment. You may wish to discuss other reliable methods of birth control with your doctor.
Do not breastfeed while you are being treated with this medicine and for 1 week after stopping the treatment.
Do not take Entrectinib with medicines known as strong CYP3A inducers or other medicinal agents that cause heart rhythm disorder. Please see the section “Can I take this with other medicines?” below for more information.
Inform your doctor if you have the following conditions:
- heart disease e.g. heart attack, heart failure (weakness and inability of the heart to pump blood)
- imbalance of essential minerals in the body
Be sure to check with your doctor or pharmacist before giving this medicine to a child. Children may be more sensitive to the side effects.
Why is it important to keep my appointments with the doctor?
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
- Your doctor needs to perform certain tests to assess if your cancer cells have a change in NTRK or ROS1 genes.
- Pregnancy tests must be done before treatment to know if this medicine is suited for you to take.
- Routine tests (e.g. liver and heart function, electrolyte and uric acid levels) may be done before starting treatment and while you are being treated with this medicine. Your doctor will advise you about how often you need to have these tests.
- Regular monitoring for signs of heart failure, fractures, eye disorders, or other serious conditions that may happen during treatment may also be needed.
Entrectinib may cause temporary loss of consciousness, dizziness, or blurred vision. If affected, do not drive or take part in any activity in which you need to be alert or need to see clearly.
Other side effects include any of the following: constipation, diarrhoea, stomach pain, difficulty swallowing, nausea, vomiting, altered taste, tiredness, pain, fever, decreased appetite, dehydration, muscle pain or weakness, headache, cough, rash, inability to completely empty the bladder when urinating, abnormal swelling of the ankles, feet or hand.
Entrectinib may also make your skin more sensitive to sunlight. Apply sunscreen when going outdoors and avoid prolonged exposure to sunlight and UV lamps.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- irregular or fast heartbeat
- chest pain that gets worse when you breathe or cough, shortness of breath or rapid, shallow breathing
- unusual changes in mood or behaviour (being too depressed, agitated), memory problems, confusion, or hallucinations (seeing, hearing or feeling things that are not existent)
- joint pain, bone pain, deformities or changes in your ability to move
- any changes or problems with your eyesight
This medicine may cause the level of your red blood cells and white blood cells to drop.
Red blood cells carry oxygen around your body. A fall in the level of red blood cells may make you feel tired and worn out.
White blood cells help your body to fight infections. A fall in the level of your white blood cells may put you at higher risk for infections, such as coughs, colds and flu, which may lead to more serious infections. Avoid crowded places and people who are sick. Inform your doctor if you have a fever, or a cough or flu that does not go away.
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Do not take Entrectinib if you are taking any of these medicines:
- medicines for epilepsy (fits or seizures) e.g. carbamazepine, phenobarbital, phenytoin
- medicine to treat lung infection known as tuberculosis e.g. rifabutin, rifampicin
- St. John’s wort (herbal medicine)
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines for HIV infection e.g. ritonavir, saquinavir
- medicines to treat fungal infection e.g. ketoconazole, itraconazole, voriconazole, posaconazole
- certain antibiotics e.g. erythromycin
This list does not include all medicines that may interact with Entrectinib.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal medicines such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Avoid excessive consumption of grapefruit or grapefruit juice (more than 1 litre a day).
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.
As this is a cancer medicine, always return any unused or expired capsule to the clinic, hospital, or pharmacy for disposal. Do not throw it away in the household waste.