Glivic (Imatinib) Tablets

• Glivec tablets contain the active ingredient imatinib mesilate, which is a type of anticancer medicine called a protein tyrosine kinase inhibitor. It is mainly used to treat cancer of the blood cells (leukaemia), but is also used to treat a rare cancer of the stomach and intestine and a type of skin cancer.
• Imatinib works by interfering with the pathways that signal certain types of cancer cells to grow.
• Leukaemia is a type of cancer that occurs when a cancerous change in a white blood cell is produced. Chronic myeloid leukaemia (CML) affects white blood cells called granulocytes. Acute lymphoblastic leukaemia (ALL) affects white blood cells called lymphocytes. In both these types of leukaemia, the cancerous change often involves an abnormal rearrangement of the chromosomes (genetic material) in the white blood cells. Leukaemic blood cells often have an abnormal chromosome called the Philadelphia chromosome (named after the place it was discovered), as well as other abnormal chromosomal arrangements.
• The abnormal chromosomes disturb the normal control of the way the blood cells divide and multiply. They cause an abnormal protein to be produced on the blood cells, called Bcr-Abl tyrosine kinase. This protein makes the white blood cells multiply without restraint and dramatically increases the number produced by the bone marrow.
• Imatinib works by targeting this abnormal protein produced by the abnormal Philadelphia chromosome. Imatinib blocks the action of this protein, which stops the cancerous cells from multiplying. The cancerous cells then die.
• Imatinib is also used to treat a rare kind of cancer that occurs in the wall of the stomach and small intestine. This cancer is called a gastrointestinal stromal tumour (GIST).
• This type of tumour is also caused by an abnormal protein that makes the cells grow and multiply abnormally. In this case the abnormal protein is also a tyrosine kinase, called c-kit. Imatinib blocks the action of this protein, which stops the cancerous cells from multiplying uncontrollably. The cancerous cells then die.
• Imatinib is also used to treat a type of skin cancer called dermatofibrosarcoma protuberans (DFSP) and works in a similar way here.
• Imatinib only acts on cancerous cells because these are the only cells that carry the abnormal tyrosine kinase. This means imatinib stops the growth of the abnormal cancerous cells, while having little effect on the growth of normal healthy cells.

How do I take it?

• The number of tablets to take, how often to take them and how long the treatment should be continued for depends on the condition being treated and how it responds to the treatment. It is important to follow the instructions given by your doctor.
• Glivec tablets should be taken with food and a large glass of water in order to minimise irritation to the gut.
• For people unable to swallow the tablets, they may be dispersed in a glass of mineral water or apple juice. The required number of tablets should be placed in the appropriate volume of drink (approximately 50ml for a 100mg tablet, and 200ml for a 400mg tablet) and stirred with a spoon. The suspension should be drunk immediately after the tablets have disintegrated.

Use with caution in

• Children.
• Elderly people.
• Decreased liver function.
• People with decreased kidney function or a history of kidney failure.
• People with a history of heart disease, eg heart failure.

People who are taking levothyroxine following removal of their thyroid gland. These people should have regular blood tests to monitor their levels of thyroid-stimulating hormone (TSH) while taking this medicine.

Not to be used in

• Breastfeeding.
• This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• The safety of this medicine during pregnancy has not been established. For this reason, it should not be used during pregnancy unless considered essential by your doctor, and only if the potential benefit to the mother outweighs any risks to the developing baby. Women who could get pregnant should use a reliable method of contraception to avoid getting pregnant while taking this medicine. Consult your doctor for further information.
• It is not known whether this medicine passes into breast milk. Mothers who need to take this medicine should not breastfeed. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

Very common (affect more than 1 in 10 people)

• Excessive fluid retention in the body tissues, resulting in swelling (oedema).
• Weight gain (see warning section above).
• Fatigue.
• Headache.
• Disturbances of the gut such as diarrhoea, nausea, vomiting, indigestion or abdominal pain.
• Rashes such as eczema or dermatitis.
• Pain in the muscles or joints.
• Muscle spasms and cramps.
• Decreased numbers of white blood cells, red blood cells or platelets in the blood.

Common (affect between 1 in 10 and 1 in 100 people)

• Loss of appetite.
• Weight loss.
• Feeling weak.
• Fever or shivering.
• Difficulty sleeping (insomnia).
• Dizziness.
• Changes in sensation such as pins and needles or tingling sensations or numbness.
• Alteration in taste.
• Dry mouth.
• Bloating or wind.
• Constipation.
• Inflammation of the lining of the eye, causing pain and redness (conjunctivitis).
• Dry or watery eyes, blurred vision or eyelid swelling.
• Flushing.
• Bleeding, eg nosebleeds.
• Shortness of breath.
• Cough.
• Dry skin or itching.
• Increased sensitivity of the skin to sunlight (photosensitivity).
• Hair loss (alopecia).
• Night sweats.

Uncommon (affect between 1 in 100 and 1 in 1000 people)

• Sleepiness.
• Infections.
• Change in skin pigmentation.
• Depression or anxiety.
• Decreased levels of potassium, sodium or phosphate in the blood (hypokalaemia, hyponatraemia or hypophosphataemia).
• Increased levels of sugar, uric acid or calcium in the blood (hyperglycaemia, hyperuricaemia or hypercalcaemia).
• Gout.
• Sexual problems such as decreased sex drive or erectile dysfunction.
• Heavy or irregular menstrual periods.
• Breast enlargement.
• Memory problems.
• Restless legs syndrome.
• Tremor.
• Bleeding in the eye.
• Swelling of the back of the eye (macular oedema).
• Hearing loss.
• Sensation of ringing or other noise in the ears (tinnitus).
• Spinning sensation (vertigo).
• Increased heart rate (tachycardia), awareness of your heartbeat (palpitations) or chest pain.
• Heart failure.
• Changes in blood pressure.
• Fluid in the lungs (pulmonary oedema).
• Cold hands and feet.
• Sore mouth or mouth ulcers.
• Bleeding in the gut. Tell your doctor if you vomit blood or notice blood in your stools or black tarry stools.
• Inflammation of the pancreas (pancreatitis).
• Inflammation of the liver (hepatitis) or jaundice (see warning section above).
• Increased need to pass urine, blood in the urine, kidney pain or acute kidney failure.

Rare (affect between 1 in 1000 and 1 in 10,000 people)

• Severe skin reactions.
• Inflammatory bowel disease.
• Liver failure.
• Lung problems, such as stiffening of the lungs (pulmonary fibrosis).
• Irregular heartbeats, angina or heart attack.
• Cataracts or glaucoma.
• Convulsions.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.

High doses of imatinib may prevent the breakdown of paracetamol by the liver. You should not take paracetamol with this medicine without first checking with your doctor or pharmacist.

Imatinib may also prevent the breakdown of the following medicines, which may increase the risk of their side effects:

• alfentanil
• benzodiazepines, eg alprazolam, triazolam
• bortezomib
• certain calcium-channel blockers, eg nifedipine
• ciclosporin
• docetaxel
• ergotamine
• fentanyl
• metoprolol
• pimozide
• quinidine
• statins, eg simvastatin
• sirolimus
• tacrolimus
• terfenadine.

Imatinib may enhance the anti-blood-clotting effect of the anticoagulant medicine warfarin. For this reason, warfarin is not recommended for people taking imatinib. People who need a medicine to prevent blood clots should be prescribed a heparin or low molecular weight heparin (eg enoxaparin) instead.

Imatinib may lower the blood level of levothyroxine in people who are taking levothyroxine because they have had their thyroid gland removed. These people should have regular blood tests to monitor their levels of thyroid-stimulating hormone (TSH) while taking imatinib.

The following medicines may increase the breakdown of imatinib by the liver, which may make it less effective. These medicines should be avoided in people taking imatinib:

• carbamazepine
• dexamethasone
• fosphenytoin
• oxcarbazepine
• phenobarbital
• phenytoin
• primidone
• rifampicin
• the herbal remedy St John's wort (Hypericum perforatum).

The following medicines may increase the blood level of imatinib, which could increase the risk of its side effects:

• azole antifungals such as ketoconazole, itraconazole, posaconazole, voriconazole
• the macrolide antibiotics erythromycin, clarithromycin and telithromycin
• protease inhibitors such as indinavir, lopinavir, ritonavir, saquinavir, telaprevir, nelfinavir, boceprevir.

There may be an increased risk of side effects on the liver or blood cells if imatinib is used in combination with chemotherapy medicines that can have side effects on these areas.

References:

http://www.netdoctor.co.uk/medicines/cancer/a8337/glivec-imatinib/

http://www.medschat.com/Discuss/glivic-183855.htm

https://www.medicines.org.uk/emc/medicine/14080

https://www.drugs.com/gleevec.html

http://www.news-medical.net/drugs/Glivec-Tablets.aspx

https://en.wikipedia.org/wiki/Imatinib