What Is Imatinib Grindeks and What Is It Used For?
Imatinib Grindeks is a targeted cancer medicine containing imatinib mesylate. It works by selectively blocking abnormal tyrosine kinase enzymes that drive the uncontrolled growth of cancer cells in several types of blood cancers and solid tumors.
Imatinib Grindeks belongs to a class of medicines called tyrosine kinase inhibitors (TKIs). These drugs represent a breakthrough in cancer treatment because they target specific molecular abnormalities in cancer cells rather than attacking all rapidly dividing cells like traditional chemotherapy. The active substance, imatinib, was one of the first targeted cancer therapies ever developed and has fundamentally transformed the treatment of several types of cancer since its initial approval in the early 2000s.
The medicine works by inhibiting the BCR-ABL tyrosine kinase, an abnormal enzyme produced by the Philadelphia chromosome. This chromosome abnormality is found in virtually all cases of chronic myeloid leukemia (CML) and in a subset of acute lymphoblastic leukemia cases. By blocking BCR-ABL, imatinib effectively stops the uncontrolled proliferation of leukemic cells and can induce disease remission in the majority of patients.
Beyond BCR-ABL, imatinib also inhibits other tyrosine kinases including c-KIT and platelet-derived growth factor receptor (PDGFR). This broader activity explains its effectiveness across multiple cancer types. Imatinib Grindeks is a generic formulation manufactured by AS Grindeks in Latvia and has been approved in the European Economic Area after demonstrating bioequivalence with the original imatinib product through rigorous regulatory assessment.
Approved Indications
Imatinib Grindeks is approved for the treatment of the following conditions in adults and, in certain cases, children:
- Chronic myeloid leukemia (CML) — A blood cancer characterized by the overproduction of abnormal white blood cells (myeloid cells). CML progresses through three phases: chronic, accelerated, and blast crisis. Imatinib is a standard first-line treatment for newly diagnosed chronic-phase CML in both adults and children aged 2 years and older.
- Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) — An aggressive form of blood cancer in which immature white blood cells (lymphoblasts) proliferate uncontrollably. Imatinib is used in combination with chemotherapy in adults and children.
- Myelodysplastic/myeloproliferative diseases (MDS/MPD) — A group of blood disorders characterized by abnormal blood cell production. Imatinib is used in the subset of patients whose disease is driven by PDGFR gene rearrangements (adults only).
- Hypereosinophilic syndrome (HES) and chronic eosinophilic leukemia (CEL) — Conditions in which eosinophils (a type of white blood cell) proliferate abnormally. Imatinib is used in a specific subset of patients with FIP1L1-PDGFRα fusion kinase (adults only).
- Gastrointestinal stromal tumors (GIST) — The most common mesenchymal tumors of the gastrointestinal tract. Imatinib targets the KIT receptor, which is mutated in approximately 85% of GIST cases. It is used for unresectable or metastatic disease and as adjuvant therapy after surgical resection (adults only).
- Dermatofibrosarcoma protuberans (DFSP) — A rare soft tissue tumor arising in the dermis. DFSP is driven by a characteristic chromosomal translocation that creates a COL1A1-PDGFB fusion gene. Imatinib is used for unresectable, recurrent, or metastatic disease (adults only).
The introduction of imatinib has dramatically improved survival outcomes, particularly in CML. Before imatinib, the 5-year survival rate for CML was approximately 30%. With imatinib therapy, long-term studies now show 5-year survival rates exceeding 90% for chronic-phase CML patients. This remarkable improvement has led the World Health Organization to include imatinib on its Model List of Essential Medicines, recognizing it as one of the most important medications worldwide.
What Should You Know Before Taking Imatinib Grindeks?
Imatinib Grindeks should only be prescribed by a physician experienced in treating blood cancers or solid tumors. Several important precautions must be considered before and during treatment, including liver and kidney function, cardiac health, and potential drug interactions.
Before starting treatment with Imatinib Grindeks, your doctor will perform a thorough medical assessment. This includes baseline blood tests to evaluate your liver function, kidney function, and blood cell counts. These tests will be repeated regularly throughout your treatment to monitor for potential complications and to assess how well the medicine is working. It is essential that you attend all scheduled appointments and follow your doctor's instructions carefully.
Your doctor needs a complete picture of your medical history to prescribe Imatinib Grindeks safely. This includes information about all current and past medical conditions, all medications you take (including over-the-counter drugs and herbal supplements), and any known allergies. Even conditions that may seem unrelated to cancer treatment can affect how imatinib works in your body or increase the risk of certain side effects.
Contraindications
Do Not Take Imatinib Grindeks If:
You are allergic to imatinib or any of the other ingredients in this medicine (listed in the composition section). If you think you may be allergic but are not sure, consult your doctor before taking this medicine. Signs of an allergic reaction may include skin rash, itching, swelling of the face or throat, or difficulty breathing.
Warnings and Precautions
Inform your doctor before starting Imatinib Grindeks if any of the following conditions apply to you:
- Liver disease: Imatinib is metabolized primarily by the liver, and pre-existing liver conditions may increase the risk of hepatotoxicity. Your doctor will monitor liver function tests closely, particularly during the first few months of treatment. Cases of liver failure and severe liver damage have been reported, including some resulting in liver transplantation or death.
- Kidney disease: Impaired kidney function may affect how imatinib is eliminated from your body. Dose adjustments may be necessary for patients with renal impairment. Long-term imatinib use has been associated with a decline in kidney function in some patients.
- Heart disease: Imatinib can cause fluid retention, which may worsen pre-existing cardiac conditions including congestive heart failure. Patients with heart failure or a history of cardiac disease require careful monitoring. Your doctor should weigh the cardiac risks against the potential benefits of treatment.
- Hepatitis B infection: If you have ever had hepatitis B, imatinib treatment may cause reactivation of the virus, which can be life-threatening in some cases. Your doctor will test for hepatitis B before starting treatment and monitor you for signs of reactivation throughout therapy.
- Thyroid disorder: If you have had your thyroid gland removed and are taking levothyroxine replacement, your doctor may need to adjust your levothyroxine dose as imatinib can interfere with thyroid hormone metabolism.
During treatment, report any of the following to your doctor immediately: rapid weight gain (which may indicate severe fluid retention), unexplained bruising or bleeding, fever, extreme fatigue, or confusion. These may be signs of thrombotic microangiopathy (TMA), a serious condition affecting blood vessels that requires urgent medical attention.
Sun Sensitivity
You may become more sensitive to sunlight while taking Imatinib Grindeks. Protect yourself by covering exposed skin when outdoors and using sunscreen with a high SPF. This precaution also applies to children receiving this medicine. Avoid prolonged sun exposure and tanning beds during treatment.
Your doctor will weigh you regularly and perform blood tests throughout your treatment to monitor your response and check for side effects. The frequency of monitoring will be highest at the start of treatment and may decrease as your treatment progresses, provided your results remain stable.
Children and Adolescents
Imatinib Grindeks is approved for children with CML (aged 2 years and older) and Ph+ ALL. There is limited experience in children with other indications such as MDS/MPD, DFSP, GIST, and HES/CEL. Some children and adolescents taking imatinib may experience slower growth than normal. This effect appears to be more pronounced in children who start treatment before puberty. Your doctor will monitor your child's growth at regular intervals throughout treatment and for an appropriate period after discontinuation.
Pregnancy and Breastfeeding
Important Information for Women of Childbearing Potential
Imatinib Grindeks is not recommended during pregnancy as it may cause harm to the developing baby. Animal studies have shown evidence of reproductive toxicity, and post-marketing reports include cases of birth defects in infants exposed to imatinib during pregnancy. Women who could become pregnant must use effective contraception during treatment and for at least 15 days after the last dose.
If you discover that you are pregnant while taking imatinib, inform your doctor immediately. Your doctor will carefully evaluate the risks and benefits of continuing treatment on an individual basis, considering the severity of your underlying condition and the potential risks to the fetus.
Breastfeeding must be avoided during treatment and for 15 days after the last dose. Both imatinib and its active metabolite are excreted in breast milk at concentrations that may be harmful to the nursing infant.
Patients concerned about fertility should discuss this with their doctor before starting treatment, as imatinib may affect fertility in both men and women.
Driving and Operating Machinery
Imatinib may cause dizziness, fatigue, or blurred vision. If you experience any of these effects, do not drive a vehicle or operate machinery until you feel well again. You are responsible for assessing your own fitness to drive or perform tasks requiring alertness and concentration.
How Does Imatinib Grindeks Interact with Other Drugs?
Imatinib has clinically significant interactions with many commonly used medicines, including antifungals, anti-epileptics, anticoagulants, and certain herbal products. Always inform your doctor about all medicines and supplements you are taking.
Imatinib is metabolized primarily by the cytochrome P450 enzyme CYP3A4 and is itself an inhibitor of CYP3A4, CYP2D6, and CYP2C9. This dual role — being both a substrate and an inhibitor of metabolic enzymes — means that imatinib can both be affected by other drugs and affect the metabolism of other drugs. Understanding these interactions is critical for safe and effective treatment, as changes in imatinib blood levels can either reduce its anticancer efficacy or increase the risk of toxicity.
Medicines that inhibit CYP3A4 (such as ketoconazole, itraconazole, clarithromycin, and erythromycin) can increase imatinib plasma concentrations, potentially leading to more pronounced side effects. Conversely, medicines that induce CYP3A4 (such as rifampicin, phenytoin, carbamazepine, phenobarbital, dexamethasone, and St. John's Wort) can substantially reduce imatinib levels and decrease its therapeutic effectiveness. In clinical studies, rifampicin co-administration reduced imatinib plasma exposure by approximately 74%, which could render the treatment ineffective.
Because imatinib itself inhibits CYP3A4 and CYP2D6, it can increase the blood levels of drugs metabolized by these enzymes. This is particularly important for drugs with a narrow therapeutic index, where even small changes in blood levels can have significant clinical consequences.
Major Interactions
| Drug / Substance | Effect | Clinical Action |
|---|---|---|
| Ketoconazole, Itraconazole | Increased imatinib levels (CYP3A4 inhibition) | Use with caution; monitor for increased side effects |
| Rifampicin | Reduced imatinib levels by up to 74% (CYP3A4 induction) | Avoid combination; alternative antimicrobials recommended |
| Phenytoin, Carbamazepine | Reduced imatinib levels (CYP3A4 induction) | Avoid combination; consider alternative anti-epileptics |
| St. John's Wort | Significantly reduced imatinib levels | Do not use concurrently with imatinib |
| Warfarin | Increased anticoagulant effect (CYP2C9 inhibition) | Switch to low-molecular-weight heparin during imatinib therapy |
Moderate Interactions
| Drug / Substance | Effect | Clinical Action |
|---|---|---|
| Simvastatin | Increased simvastatin levels (CYP3A4 inhibition by imatinib) | Monitor for myopathy; consider dose reduction or alternative statin |
| Cyclosporine | Increased cyclosporine levels | Monitor cyclosporine blood levels closely |
| Levothyroxine | Potential for altered thyroid hormone levels | Monitor TSH levels; adjust levothyroxine dose as needed |
| Paracetamol (Acetaminophen) | Imatinib inhibits paracetamol O-glucuronidation | Use with caution, especially at high paracetamol doses |
| Grapefruit juice | May increase imatinib levels (CYP3A4 inhibition) | Avoid grapefruit juice during treatment |
Always inform your doctor, pharmacist, or nurse about all medicines you are taking, including prescription medicines, over-the-counter medicines, vitamins, and herbal supplements. Some interactions can be dangerous, and your doctor may need to adjust your imatinib dose, change the dose of another medicine, or choose an alternative medication to avoid a harmful interaction.
What Is the Correct Dosage of Imatinib Grindeks?
The dosage of Imatinib Grindeks varies depending on the specific condition being treated, ranging from 100 mg to 800 mg daily. Always take this medicine exactly as your doctor has prescribed, with food and a large glass of water.
Your doctor will determine the exact dose of Imatinib Grindeks based on your specific condition, disease phase and severity, treatment response, and tolerability. Do not change your dose or stop taking this medicine without consulting your doctor, even if you feel better or your symptoms improve. Discontinuing treatment prematurely may allow the cancer to return or progress. Regular blood tests and clinical assessments will guide any dose adjustments throughout your treatment.
Adult Dosing
| Condition | Starting Dose | Maximum Dose | Administration |
|---|---|---|---|
| CML (chronic phase) | 400 mg once daily | 800 mg daily | 4 capsules once daily; if 800 mg, split into two doses |
| CML (accelerated/blast crisis) | 600 mg once daily | 800 mg daily | 6 capsules once daily; if 800 mg, split into two doses |
| Ph+ ALL | 600 mg once daily | 600 mg daily | 6 capsules once daily |
| GIST | 400 mg once daily | 800 mg daily | 4 capsules once daily; if 800 mg, split into two doses |
| MDS/MPD | 400 mg once daily | 400 mg daily | 4 capsules once daily |
| HES/CEL | 100 mg once daily | 400 mg daily | 1 capsule once daily; may be increased based on response |
| DFSP | 800 mg daily | 800 mg daily | 4 capsules morning + 4 capsules evening |
Your doctor may increase or decrease your dose depending on how you respond to treatment. For CML and GIST, a dose increase to 800 mg daily (given as 400 mg twice daily) may be considered if the disease progresses or if the initial response is insufficient. Dose reductions may be necessary if you develop significant side effects, particularly low blood cell counts or liver toxicity.
Children and Adolescents
Pediatric Dosing
Dosing for children is calculated by the doctor based on body surface area (BSA), which takes into account the child's weight and height. The dose is typically given as mg/m²/day. The total daily dose for children should not exceed:
- CML: Maximum 800 mg per day
- Ph+ ALL: Maximum 600 mg per day
Treatment may be given as a single daily dose or split into two equal doses (morning and evening). There is no clinical experience with imatinib in children under 2 years of age with CML, and very limited experience in children with Ph+ ALL and other indications.
How to Take Imatinib Grindeks
- Take with food and a large glass of water to help protect against stomach problems and improve tolerability.
- Swallow the capsules whole. Do not open or crush them unless you have difficulty swallowing.
- If you cannot swallow the capsules, you may open them and dissolve the powder contents in a glass of still (non-carbonated) water or apple juice. Women of childbearing potential should handle the capsule contents with care, avoiding skin, eye, or inhalation exposure. Wash hands immediately after handling opened capsules.
- Continue taking the medicine for as long as your doctor prescribes. Do not stop treatment on your own, even if you feel well.
Missed Dose
If You Forget a Dose
Take it as soon as you remember, unless it is nearly time for your next scheduled dose. In that case, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a forgotten one. If you have questions about what to do, contact your doctor or pharmacist.
Overdose
If You Take Too Much
If you have taken more Imatinib Grindeks than prescribed, or if a child has accidentally taken this medicine, contact a doctor, hospital emergency department, or poison control center immediately for assessment and advice. Bring the medicine packaging with you. You may require medical treatment and monitoring.
What Are the Side Effects of Imatinib Grindeks?
Like all medicines, Imatinib Grindeks can cause side effects, although not everybody gets them. The most common side effects include nausea, fluid retention, muscle cramps, and skin rash. Some side effects can be serious and require immediate medical attention.
Side effects of imatinib are grouped below by how frequently they occur. It is important to understand that many side effects are mild to moderate and can be managed with supportive care or dose adjustments. Your doctor will help you manage side effects through anti-nausea medicines, dose modifications, or temporary treatment interruptions as needed. However, some side effects can be serious and require prompt medical attention.
The type and severity of side effects may vary depending on the condition being treated and the dose of imatinib. Patients with advanced-stage CML or GIST may be more likely to experience certain side effects compared to those with chronic-phase CML. Your doctor will discuss the specific risks relevant to your situation.
Seek Immediate Medical Attention If You Experience:
- Rapid weight gain or severe swelling (signs of fluid retention)
- Signs of infection: fever, chills, sore throat, mouth sores
- Unexpected bleeding or bruising without injury
- Chest pain or irregular heartbeat
- Severe abdominal pain, blood in vomit or stool, black-colored stool
- Yellowing of skin or eyes, dark urine, loss of appetite (signs of liver damage)
- Severe skin reactions: widespread rash, blistering, peeling skin
- Sudden severe headache, weakness or paralysis of limbs or face, difficulty speaking (signs of stroke)
- Significantly reduced urine output with excessive thirst (signs of kidney problems)
Very Common
May affect more than 1 in 10 people
- Nausea, vomiting, diarrhea, indigestion
- Fluid retention and swelling (periorbital edema, facial swelling, leg edema)
- Muscle cramps, pain in muscles, joints, or bones
- Skin rash
- Headache or fatigue
- Weight gain
- Decreased blood cell counts: neutropenia, thrombocytopenia, anemia (detected in blood tests)
Common
May affect up to 1 in 10 people
- Loss of appetite, weight loss, or taste disturbances
- Dizziness or weakness
- Insomnia (difficulty sleeping)
- Watery or itchy eyes, conjunctivitis, blurred vision
- Nosebleeds
- Abdominal pain, bloating, flatulence, heartburn, constipation
- Itching or unexpected hair loss/thinning
- Numbness or tingling in hands and feet (peripheral neuropathy)
- Mouth sores, dry mouth, dry skin, or dry eyes
- Joint swelling
- Hot flushes, chills, or night sweats
Uncommon
May affect up to 1 in 100 people
- Chest pain, irregular heartbeat (cardiac problems)
- Cough, difficulty breathing, painful breathing (pulmonary issues)
- Nausea with dark urine, yellowing of skin/eyes (liver damage)
- Severe skin reactions: blistering, peeling, purpuric rash
- Reduced urine output, excessive thirst (kidney problems)
- Eye pain, vision deterioration, bleeding in the eyes
- Depression, anxiety, drowsiness
- Migraine, tremor, memory impairment
- High blood pressure (hypertension)
- Restless legs syndrome, tinnitus (ringing in ears)
- Erectile dysfunction, menstrual irregularities
- Nail discoloration, folliculitis, exfoliative dermatitis
- Gastric ulcer, painful skin nodules (panniculitis)
Rare and Very Rare
May affect up to 1 in 1,000 people or fewer
- Confusion
- Thrombotic microangiopathy (blood clots in small blood vessels)
- Osteonecrosis (bone death with pain in affected area)
- Pemphigus (blistering of skin or mucous membranes)
- Raynaud's syndrome (cold, numb, discolored fingers and toes)
- Hearing impairment
- Cellulitis (sudden skin redness and swelling)
- Hepatitis B reactivation
- Chronic kidney failure
Additionally, some side effects have been reported with unknown frequency, including severe allergic reactions combining widespread rash, fever, jaundice, and organ involvement (drug reaction with eosinophilia and systemic symptoms — DRESS syndrome), palmar-plantar erythrodysesthesia (painful redness and swelling of palms and soles), and slowed growth in children and adolescents.
If you experience any side effect, including any not listed here, tell your doctor, pharmacist, or nurse. You can also report suspected side effects directly to your national pharmacovigilance authority to help continuously monitor the benefit-risk balance of this medicine.
How Should You Store Imatinib Grindeks?
Store Imatinib Grindeks at room temperature, out of reach of children, and always check the expiry date before use. No special storage conditions are required.
Keep this medicine out of the sight and reach of children at all times. This is especially important for cancer medicines, which can be harmful if taken accidentally by someone for whom they are not prescribed.
Do not use Imatinib Grindeks after the expiry date stated on the carton and blister packaging after “EXP.” The expiry date refers to the last day of the stated month. No special storage temperature or humidity conditions are required for this medicine.
Do not use this medicine if you notice that the packaging is damaged or shows visible signs of tampering. Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures help protect the environment from pharmaceutical contamination.
Imatinib Grindeks 100 mg hard capsules are brown-orange and 19 mm long. They are packaged in PVC/PVDC/aluminium blisters containing 10 capsules each. Available pack sizes are 60 or 120 capsules. Not all pack sizes may be marketed in your country.
What Does Imatinib Grindeks Contain?
Each capsule contains imatinib mesylate equivalent to 100 mg imatinib as the active ingredient, along with standard pharmaceutical excipients in a hard gelatin capsule shell.
Active Ingredient
The active substance is imatinib (as mesylate). Each Imatinib Grindeks hard capsule contains imatinib mesylate equivalent to 100 mg of imatinib. Imatinib mesylate is the salt form of imatinib that provides optimal bioavailability and stability in the capsule formulation.
Other Ingredients (Excipients)
- Capsule contents: Microcrystalline cellulose, colloidal anhydrous silica, crospovidone, talc, magnesium stearate
- Capsule shell: Titanium dioxide (E 171), iron oxide red (E 172), iron oxide yellow (E 172), gelatin
Appearance
Imatinib Grindeks 100 mg capsules are brown-orange hard gelatin capsules, approximately 19 mm in length. The contents are a white to light yellow or brownish-yellow powder. If you notice any change in the appearance of the capsules or their contents, do not take them and consult your pharmacist.
Marketing Authorization Holder
AS Grindeks, Krustpils iela 53, Riga, LV-1057, Latvia. Imatinib Grindeks is approved in multiple countries within the European Economic Area including Belgium, Estonia, France, Latvia, Lithuania, Romania, Slovakia, Spain, the United Kingdom (Northern Ireland), Sweden, Czech Republic, Hungary, and Austria.