Imatinib Amarox
Tyrosine Kinase Inhibitor for Leukaemia, GIST and Other Cancers
Quick Facts About Imatinib Amarox
Key Takeaways About Imatinib Amarox
- Targeted cancer therapy: Imatinib selectively blocks BCR-ABL, c-Kit and PDGFR tyrosine kinases, stopping the growth of specific cancer cells while largely sparing normal cells
- Transformed CML prognosis: Before imatinib, the median survival for CML was 3–5 years; with imatinib, the 10-year overall survival rate exceeds 80%
- Take with food: Always take imatinib with a meal and a large glass of water to reduce gastrointestinal side effects
- Regular blood monitoring required: Your doctor will perform regular blood tests to check blood cell counts, liver function, and kidney function throughout treatment
- Many drug interactions: Imatinib is metabolised by CYP3A4 and interacts with numerous other medicines – always inform your doctor of all medications, including herbal products
What Is Imatinib Amarox and What Is It Used For?
Imatinib Amarox is a tyrosine kinase inhibitor (TKI) that works by blocking specific enzymes responsible for the uncontrolled growth of abnormal cells. It is used to treat several types of cancer and blood disorders, including chronic myeloid leukaemia (CML), gastrointestinal stromal tumours (GIST), and Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ ALL).
Imatinib belongs to a class of medicines known as protein kinase inhibitors. It was developed as a targeted therapy – meaning it specifically blocks the abnormal proteins that drive certain cancers, rather than affecting all rapidly dividing cells like traditional chemotherapy. This targeted approach generally results in fewer side effects and better quality of life during treatment compared with conventional cytotoxic chemotherapy.
The primary target of imatinib is the BCR-ABL fusion protein, a constitutively active tyrosine kinase created by the Philadelphia chromosome translocation. This abnormal chromosome is found in virtually all cases of CML and in a subset of patients with ALL. By blocking BCR-ABL, imatinib effectively stops the proliferation of the malignant white blood cells and induces their programmed cell death (apoptosis). This has fundamentally changed CML from a disease that was once invariably fatal within a few years to a manageable chronic condition with near-normal life expectancy for most patients.
Imatinib also inhibits several other tyrosine kinase receptors, including the c-Kit receptor (also known as stem cell factor receptor), the platelet-derived growth factor receptors (PDGFR-alpha and PDGFR-beta), and the discoidin domain receptors (DDR1 and DDR2). These additional targets make imatinib effective against a range of other malignancies driven by these pathways.
Approved Indications in Adults
Imatinib Amarox is approved for the treatment of the following conditions in adult patients:
- Chronic myeloid leukaemia (CML) – a cancer of the white blood cells in which myeloid cells grow out of control. Imatinib is used in all phases of CML (chronic phase, accelerated phase, and blast crisis) and is the standard first-line treatment.
- Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ ALL) – an aggressive form of leukaemia where immature white blood cells (lymphoblasts) grow uncontrollably. Imatinib is used in combination with chemotherapy or as monotherapy.
- Myelodysplastic/myeloproliferative diseases (MDS/MPD) – a group of blood disorders characterised by abnormal blood cell production. Imatinib is effective in the subset of patients whose disease is driven by PDGFR gene rearrangements.
- Hypereosinophilic syndrome (HES) and/or chronic eosinophilic leukaemia (CEL) – blood disorders involving excessive eosinophils. Imatinib is used in patients with specific FIP1L1-PDGFR-alpha fusion genes or those who respond to imatinib.
- Gastrointestinal stromal tumours (GIST) – a cancer arising from the supportive tissue of the stomach and intestines, driven by activating mutations in c-Kit or PDGFR-alpha. Imatinib is used in unresectable and/or metastatic GIST and as adjuvant therapy after surgical resection.
- Dermatofibrosarcoma protuberans (DFSP) – a rare soft-tissue sarcoma of the skin. Imatinib is used for unresectable, recurrent or metastatic DFSP in adult patients who are not eligible for surgery.
Use in Children and Adolescents
Imatinib Amarox is also approved for use in children and adolescents for:
- CML (chronic phase) – in children aged 2 years and older, or in those who have relapsed after stem cell transplantation or who are resistant to interferon-alpha therapy
- Ph+ ALL – in children, typically as part of a combination chemotherapy regimen
There is limited experience with imatinib in children for the other approved indications (MDS/MPD, DFSP, GIST and HES/CEL).
Imatinib (originally marketed as Gleevec/Glivec) was first approved by the FDA in 2001 and is considered one of the most important advances in cancer therapy. It is included on the World Health Organization's List of Essential Medicines. Today, multiple generic formulations are available worldwide, including Imatinib Amarox and Imatinib Sandoz, making this life-saving treatment more accessible.
What Should You Know Before Taking Imatinib Amarox?
Before starting Imatinib Amarox, your doctor should be informed about all your medical conditions, especially liver, kidney or heart disease, history of hepatitis B, and all other medications you take. Imatinib will only be prescribed by a doctor experienced in treating cancer or blood disorders.
Imatinib Amarox is a potent medication that requires careful medical supervision throughout treatment. Your doctor will perform baseline blood tests, assess your organ function, and review your full medical history before initiating therapy. Follow all of your doctor's instructions carefully, even if they differ from the general information in this article.
Contraindications
You should not take Imatinib Amarox if:
- You are allergic to imatinib or any other ingredient in this medicine (see the Contents section for a full list of ingredients). Allergic reactions may include skin rash, itching, swelling of the face or throat, or difficulty breathing.
If you think you may be allergic but are not sure, consult your doctor before taking this medicine.
Warnings and Precautions
Talk to your doctor before taking Imatinib Amarox if any of the following apply to you:
- Liver disease – imatinib is extensively metabolised by the liver. Patients with hepatic impairment may have increased exposure to imatinib and require dose adjustments or more frequent monitoring of liver function tests.
- Kidney disease – although imatinib is primarily eliminated via the liver, renal impairment may affect overall drug clearance. Your doctor may need to adjust your dose.
- Heart disease – imatinib may cause fluid retention, which can worsen pre-existing cardiac conditions. Cases of left ventricular dysfunction and congestive heart failure have been reported, particularly in elderly patients and those with comorbidities.
- Thyroidectomy and levothyroxine use – if you are taking levothyroxine because your thyroid has been removed, imatinib may reduce levothyroxine levels. Your thyroid function should be monitored regularly during treatment.
- History of hepatitis B – imatinib can cause reactivation of hepatitis B virus, which in some cases can be fatal. Your doctor will test for hepatitis B before starting treatment and monitor you for signs of reactivation.
- Rapid weight gain (a sign of severe fluid retention)
- Bruising, bleeding, fever, tiredness and confusion (signs of thrombotic microangiopathy, or TMA)
- Signs of infection such as fever, chills, sore throat or mouth sores
- Yellowing of the skin or eyes (signs of liver damage)
Sun sensitivity: You may become more sensitive to sunlight while taking imatinib. It is important to cover exposed areas of skin and use a high-SPF sunscreen. This precaution also applies to children taking this medicine.
Growth in children: Some children and adolescents taking imatinib may grow more slowly than normal. Your doctor will regularly monitor your child's growth during treatment.
Regular monitoring: Throughout treatment with Imatinib Amarox, your doctor will regularly check whether the medicine is working. You will also have regular blood tests and be weighed regularly to monitor for fluid retention.
Pregnancy and Breastfeeding
Imatinib Amarox is not recommended during pregnancy unless clearly necessary, as it may harm the developing baby. Animal studies have shown adverse effects, and there is limited human data.
- Women of childbearing potential should use effective contraception during treatment and for at least 15 days after the last dose.
- Do not breastfeed during treatment with imatinib and for at least 15 days after the last dose, as the drug may pass into breast milk and could harm the infant.
- Fertility concerns: Patients who are concerned about the potential effects of imatinib on their fertility should discuss this with their doctor before starting treatment. Fertility preservation options may be available.
Driving and Operating Machinery
Imatinib can cause dizziness, blurred vision, or drowsiness. If you experience any of these symptoms, you should not drive or operate machinery until you feel well again. You are responsible for assessing whether you are fit to drive or perform tasks that require alertness.
How Does Imatinib Amarox Interact with Other Drugs?
Imatinib interacts with many other medications because it is metabolised by the liver enzyme CYP3A4 and also inhibits several CYP enzymes itself. Strong CYP3A4 inhibitors increase imatinib levels, while CYP3A4 inducers decrease them. Imatinib can also raise or lower levels of other drugs. Always tell your doctor about all medications you are taking.
Imatinib is primarily metabolised by the cytochrome P450 enzyme CYP3A4, and also by CYP1A2, CYP2D6, CYP2C9, and CYP2C19 to a lesser extent. Additionally, imatinib itself inhibits CYP3A4, CYP2D6, CYP2C9, and CYP2C19. This means imatinib both is affected by and affects the metabolism of many other drugs. The following tables summarise the most clinically important interactions.
Major Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| Ketoconazole / Itraconazole | Antifungal | Strong CYP3A4 inhibitors that significantly increase imatinib blood levels | Avoid combination if possible; if required, monitor closely for toxicity |
| Rifampicin | Antibiotic (TB treatment) | Strong CYP3A4 inducer that can reduce imatinib plasma levels by up to 74% | Avoid combination; use alternative antimicrobial agent if possible |
| Phenytoin / Carbamazepine | Anticonvulsants | CYP3A4 inducers that significantly reduce imatinib effectiveness | Use alternative anticonvulsant (e.g. levetiracetam, valproate) |
| Warfarin | Anticoagulant | Imatinib inhibits warfarin metabolism via CYP2C9, increasing bleeding risk | Switch to low-molecular-weight heparin; if warfarin is essential, monitor INR very closely |
| St. John's Wort (Hypericum perforatum) | Herbal supplement | CYP3A4 inducer that can significantly reduce imatinib levels | Do not use concurrently with imatinib |
Moderate Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| Simvastatin | Cholesterol-lowering (statin) | Imatinib inhibits CYP3A4, increasing simvastatin levels and risk of myopathy | Use alternative statin (e.g. pravastatin, rosuvastatin) not metabolised by CYP3A4 |
| Cyclosporine | Immunosuppressant | Imatinib may alter cyclosporine blood levels through CYP3A4 inhibition | Monitor cyclosporine levels closely; adjust dose as needed |
| Levothyroxine | Thyroid hormone | Imatinib may reduce levothyroxine levels in thyroidectomised patients | Monitor TSH regularly; dose increase of levothyroxine may be needed |
| Clarithromycin / Erythromycin | Macrolide antibiotics | Moderate CYP3A4 inhibitors that increase imatinib levels | Monitor for imatinib toxicity; consider alternative antibiotic |
| Paracetamol (Acetaminophen) | Analgesic / Antipyretic | Imatinib inhibits the O-glucuronidation of paracetamol at therapeutic doses | Use paracetamol with caution; avoid high doses |
| Metoprolol | Beta-blocker | Imatinib inhibits CYP2D6, potentially increasing metoprolol levels | Monitor heart rate and blood pressure; dose adjustment may be needed |
This list is not exhaustive. Always inform your doctor, pharmacist, or nurse about all medicines you are taking, have recently taken, or might take – including over-the-counter products, vitamins, and herbal supplements. Some medicines can affect how Imatinib Amarox works, and Imatinib Amarox can affect how other medicines work.
If you are taking medicines that prevent blood clot formation (anticoagulants), tell your doctor, as imatinib may alter their effectiveness and increase the risk of bleeding.
What Is the Correct Dosage of Imatinib Amarox?
The dose of Imatinib Amarox depends on the condition being treated. For CML, the usual adult starting dose is 400 mg or 600 mg once daily. For GIST, the starting dose is 400 mg once daily. Always take imatinib with a meal and a large glass of water. Your doctor will determine the exact dose for you.
Always take Imatinib Amarox exactly as your doctor or pharmacist has told you. It is important that you continue treatment for as long as your doctor tells you. Do not stop taking imatinib without consulting your doctor first, even if you feel better, as your condition may return.
Adults
Chronic Myeloid Leukaemia (CML)
Starting dose: 400 mg or 600 mg once daily, depending on the phase of disease
Maximum dose: 800 mg daily (400 mg twice daily – morning and evening)
Your doctor may prescribe a higher or lower dose depending on how you respond to treatment. If the daily dose is 800 mg, take 400 mg in the morning and 400 mg in the evening.
Ph-Positive Acute Lymphoblastic Leukaemia (Ph+ ALL)
Starting dose: 600 mg once daily
Treatment is typically combined with chemotherapy regimens as directed by your oncologist.
Gastrointestinal Stromal Tumours (GIST)
Starting dose: 400 mg once daily
Your doctor may increase or decrease the dose depending on your response and tolerability.
Myelodysplastic/Myeloproliferative Diseases (MDS/MPD)
Starting dose: 400 mg once daily
Hypereosinophilic Syndrome (HES) / Chronic Eosinophilic Leukaemia (CEL)
Starting dose: 100 mg once daily
Maximum dose: 400 mg once daily, depending on response
Dermatofibrosarcoma Protuberans (DFSP)
Dose: 800 mg daily (400 mg in the morning and 400 mg in the evening)
A 400 mg dose may be taken as 4 tablets of 100 mg. A 600 mg dose may be taken as 6 tablets of 100 mg.
Children and Adolescents
Your doctor will tell you how many tablets to give your child. The dose is based on your child's body weight and height, as well as the condition being treated. The total daily dose in children should not exceed 800 mg for CML or 600 mg for Ph+ ALL. The daily dose may be given as a single dose or split into two doses (half in the morning and half in the evening). There is no experience with imatinib in children with CML under the age of 2 years.
How to Take Imatinib Amarox
- Take with a meal and a large glass of water to help protect against stomach problems
- Swallow the tablets whole
- The tablets can be split in half along the score line if needed
- If you cannot swallow tablets, you can dissolve them in non-carbonated water or apple juice: use approximately 50 ml per 100 mg tablet, stir until fully dissolved, then drink the entire contents immediately
Missed Dose
If you forget to take a dose, take it as soon as you remember. However, if it is nearly time for your next dose, skip the missed dose and continue with your normal schedule. Do not take a double dose to make up for a missed one.
Overdose
If you accidentally take too many tablets, contact your doctor or go to hospital immediately. Take the medicine package with you so that hospital staff can identify what you have taken. An overdose of imatinib may increase the risk of severe side effects including severe nausea, vomiting, diarrhoea, muscle pain, fluid retention, liver damage, and bone marrow suppression.
What Are the Side Effects of Imatinib Amarox?
Like all medicines, imatinib can cause side effects, although not everyone gets them. The most common side effects include nausea, vomiting, diarrhoea, muscle cramps, musculoskeletal pain, oedema (fluid retention), skin rash, fatigue and headache. Some side effects can be serious and require immediate medical attention.
Most side effects of imatinib are mild to moderate in severity. They tend to be more common during the first months of treatment and may improve over time. However, some side effects can be serious or even life-threatening. Your doctor will monitor you closely with regular blood tests and clinical examinations.
- Rapid weight gain (sign of severe fluid retention)
- Signs of infection – fever, chills, sore throat, mouth sores
- Unexpected bleeding or bruising (sign of low platelets)
- Chest pain or irregular heartbeat
- Severe shortness of breath or cough (sign of lung or heart problems)
- Dark urine, yellowing of skin/eyes, nausea with loss of appetite (sign of liver damage)
- Severe abdominal pain, blood in stool or vomit, black-coloured stools
- Severe headache, weakness, paralysis, difficulty speaking or sudden loss of consciousness (signs of CNS problems)
- Severe skin reactions – rash with blisters, peeling skin, or pus-filled spots
Very Common
May affect more than 1 in 10 people
- Nausea, vomiting, diarrhoea, or indigestion
- Headache or fatigue
- Skin rash
- Muscle cramps, pain in joints, muscles, or bones
- Oedema (swelling, particularly around the eyes and in the legs)
- Weight gain
- Fluid retention (severe cases may be serious)
- Reduced blood cell counts (neutropenia, anaemia, thrombocytopenia)
Common
May affect up to 1 in 10 people
- Decreased appetite, weight loss, or taste disturbances
- Dizziness or weakness
- Sleep problems (insomnia)
- Watery or itchy eyes (conjunctivitis), blurred vision
- Nosebleeds
- Abdominal pain, bloating, flatulence, heartburn, constipation
- Itching or unusual hair loss/thinning
- Numbness in hands or feet
- Mouth sores
- Dry mouth, dry skin, or dry eyes
- Hot flushes, chills, or night sweats
Uncommon
May affect up to 1 in 100 people
- Chest pain, irregular heartbeat (signs of cardiac problems)
- Cough, difficulty breathing, or painful breathing (signs of lung problems)
- Feeling lightheaded, dizzy, or faint (signs of low blood pressure)
- Skin rash with blisters, redness, peeling (signs of serious skin reactions)
- Severe abdominal pain, blood in vomit or stools (signs of GI problems)
- Significantly reduced urine output, excessive thirst (signs of kidney problems)
- Eye pain, worsening vision, or bleeding in the eyes
- Bone or joint pain (signs of osteonecrosis)
- Depression, anxiety, memory problems
- Migraine, tremor, restless legs
- Tinnitus (ringing in the ears), hearing loss
- High blood pressure
- Erectile dysfunction, menstrual irregularities
Rare
May affect up to 1 in 1,000 people
- Severe skin reactions with widespread rash, nausea, fever (drug reaction with eosinophilia and systemic symptoms – DRESS)
- Thrombotic microangiopathy (TMA) – blood clots in small vessels
- Confusion
- Nail discolouration
Not Known
Frequency cannot be estimated from available data
- Redness and/or swelling of palms and soles, possibly with tingling or burning pain (hand-foot syndrome)
- Hepatitis B reactivation in patients with prior infection
- Chronic kidney failure
- Slowed growth in children and adolescents
It is important to report suspected side effects after a medicine has been authorised. This allows continuous monitoring of the medicine's benefit-risk balance. Healthcare professionals and patients are encouraged to report any suspected adverse reactions to their national regulatory authority.
How Should You Store Imatinib Amarox?
Store Imatinib Amarox out of the sight and reach of children. Do not use after the expiry date printed on the packaging. No special storage conditions are required. If supplied in an HDPE bottle, use within 3 months of first opening.
Keep this medicine in its original packaging to protect it from light and moisture. Do not use Imatinib Amarox after the expiry date stated on the blister, bottle label, or carton after “EXP”. The expiry date refers to the last day of that month.
Do not use this medicine if any packaging is damaged or shows signs of tampering. For HDPE bottles, the medicine should be used within three months after first opening the bottle.
No special temperature storage requirements apply. Store at room temperature. Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines that are no longer needed. These measures help to protect the environment.
What Does Imatinib Amarox Contain?
Each Imatinib Amarox 100 mg film-coated tablet contains 100 mg of imatinib (as imatinib mesylate). The tablets are white to off-white, round, with a score line, marked “H” on one side and “19” on the other.
Active Substance
The active substance is imatinib mesylate. Each film-coated tablet contains imatinib mesylate equivalent to 100 mg of imatinib.
Other Ingredients
- Tablet core: Magnesium stearate
- Film coating: Macrogol (E1521), talc (E553B), hypromellose (E464), titanium dioxide (E171)
Appearance and Pack Sizes
Imatinib Amarox 100 mg film-coated tablets are white to off-white, round with a bevelled edge and a score line, marked “H” on one side and “19” on the other side, with the score line between “1” and “9”. The tablet can be divided into two equal halves.
The tablets are available in blister packs of 20, 60, 90, 120, or 180 film-coated tablets, or in HDPE bottles containing 90 film-coated tablets. Not all pack sizes may be marketed.
Marketing Authorisation Holder
Amarox Pharma B.V., Rouboslaan 32, 2252 TR Voorschoten, Netherlands.
Frequently Asked Questions About Imatinib Amarox
Imatinib Amarox is a tyrosine kinase inhibitor used to treat several types of cancer and blood disorders. Its primary indications include chronic myeloid leukaemia (CML), Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ ALL), gastrointestinal stromal tumours (GIST), myelodysplastic/myeloproliferative diseases (MDS/MPD), hypereosinophilic syndrome (HES), chronic eosinophilic leukaemia (CEL), and dermatofibrosarcoma protuberans (DFSP). It works by blocking the specific tyrosine kinase proteins that drive the growth of cancer cells in these conditions.
The most common side effects of imatinib (affecting more than 1 in 10 patients) include nausea, vomiting, diarrhoea, muscle cramps, musculoskeletal pain, oedema (fluid retention – especially swelling around the eyes and in the legs), skin rash, fatigue, and headache. Most of these side effects are mild to moderate and may improve over time. Your doctor will monitor you regularly with blood tests to check for changes in blood counts and organ function.
Take Imatinib Amarox with a meal and a large glass of water to help protect against stomach problems. Swallow the tablets whole. If you cannot swallow tablets, you can dissolve them in approximately 50 ml of non-carbonated water or apple juice per 100 mg tablet, stir until dissolved, and drink immediately. Take your dose at the same time each day. Do not stop taking the medicine unless your doctor tells you to.
Imatinib is not recommended during pregnancy as it may harm the developing baby. Women of childbearing potential should use effective contraception during treatment and for 15 days after the last dose. Breastfeeding should be avoided during treatment and for 15 days after the last dose. If you are concerned about the effects of imatinib on your fertility, discuss this with your doctor before starting treatment, as fertility preservation options may be available.
The duration of treatment depends on the condition being treated and your individual response. For CML, treatment is typically long-term and may continue for many years. Some patients who achieve a deep and sustained molecular response may be eligible to attempt treatment-free remission under close medical supervision. For GIST, the duration varies depending on the clinical setting (adjuvant versus advanced disease). Your doctor will determine the appropriate duration based on your specific circumstances and treatment response.
Regular blood monitoring is essential during imatinib treatment. Your doctor will check complete blood counts (white blood cells, red blood cells, platelets), liver function tests (ALT, AST, bilirubin), kidney function tests, and monitor your weight. Blood tests are typically performed weekly during the first month, every two weeks during the second month, and then periodically (usually monthly to quarterly) thereafter. More frequent monitoring may be needed if dose adjustments are made or if abnormalities are detected.
References
- Druker BJ, Guilhot F, O'Brien SG, et al. Five-year follow-up of patients receiving imatinib for chronic myeloid leukemia. N Engl J Med. 2006;355(23):2408-2417. doi:10.1056/NEJMoa062867
- Hochhaus A, Larson RA, Guilhot F, et al. Long-term outcomes of imatinib treatment for chronic myeloid leukemia. N Engl J Med. 2017;376(10):917-927. doi:10.1056/NEJMoa1609324
- European Medicines Agency (EMA). Imatinib – Summary of Product Characteristics. Accessed January 2026.
- National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Chronic Myeloid Leukemia. Version 1.2025.
- Demetri GD, von Mehren M, Blanke CD, et al. Efficacy and safety of imatinib mesylate in advanced gastrointestinal stromal tumors. N Engl J Med. 2002;347(7):472-480. doi:10.1056/NEJMoa020461
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List, 2023. Geneva: WHO; 2023.
- European Society for Medical Oncology (ESMO). Chronic Myeloid Leukaemia: ESMO Clinical Practice Guidelines. Ann Oncol. 2020;31(2):171-185.
- Baccarani M, Deininger MW, Rosti G, et al. European LeukemiaNet recommendations for the management of chronic myeloid leukemia: 2013. Blood. 2013;122(6):872-884. doi:10.1182/blood-2013-05-501569
- British National Formulary (BNF). Imatinib. National Institute for Health and Care Excellence (NICE). Accessed January 2026.
- Joensuu H, Eriksson M, Sundby Hall K, et al. Adjuvant imatinib for high-risk GI stromal tumor: analysis of a randomized trial. J Clin Oncol. 2016;34(3):244-250. doi:10.1200/JCO.2015.62.9170
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