Gleevec 400mg Tablets

Imatinib is a small molecule tyrosine kinase inhibitor. It inhibits the Bcr-Abl tyrosine kinase, which is the oncogenic driver in Chronic Myeloid Leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). It also inhibits the receptor tyrosine kinases KIT (CD117) and Platelet-Derived Growth Factor Receptor (PDGFR), which are involved in the pathogenesis of Gastrointestinal Stromal Tumors (GIST) and other diseases.

Urgent Side Effects: Seek Medical Help Right Away

While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:

Allergic reactions: Rash, hives, itching, red, swollen, blistered, or peeling skin with or without fever, wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Infections: Fever, chills, severe sore throat, ear or sinus pain, cough, increased or changed sputum, painful urination, mouth sores, or unhealing wounds.
Bleeding: Vomiting or coughing up blood, coffee ground-like vomit, blood in urine, black, red, or tarry stools, gum bleeding, abnormal vaginal bleeding, unexplained bruises, or uncontrollable bleeding.
Electrolyte problems: Mood changes, confusion, muscle pain, cramps, or spasms, weakness, shakiness, balance changes, abnormal heartbeat, seizures, loss of appetite, or severe nausea and vomiting.
Kidney problems: Inability to urinate, changes in urine output, blood in urine, or significant weight gain.
Cardiovascular issues: Chest pain or pressure.
Neurological symptoms: Abnormal burning, numbness, or tingling sensations.
Vision changes: Changes in eyesight, eye pain, or severe eye irritation.
Depression: Changes in mood or emotional well-being.
Bone pain: Pain or discomfort in the bones.

Fluid Retention and Heart Failure

This medication may cause fluid retention, leading to swelling, weight gain, or breathing difficulties. If you experience any of these symptoms, contact your doctor. Additionally, heart failure has been reported in patients taking this medication, including those with pre-existing heart disease. If you have heart disease, inform your doctor and seek medical attention immediately if you experience:

Shortness of breath
Significant weight gain
Abnormal heartbeat
New or worsening swelling in the arms or legs

Liver Problems

Severe and potentially life-threatening liver problems have been reported with this medication. If you experience any of the following symptoms, contact your doctor immediately:

Dark urine
Fatigue
Decreased appetite
Nausea or stomach pain
Light-colored stools
Vomiting
Yellow skin or eyes

Tumor Lysis Syndrome (TLS)

Patients with cancer taking this medication may be at increased risk of developing TLS, a potentially life-threatening condition. If you experience any of the following symptoms, contact your doctor immediately:

Abnormal or rapid heartbeat
Fainting
Difficulty urinating
Muscle weakness or cramps
Nausea, vomiting, diarrhea, or loss of appetite
Feeling sluggish

Severe Skin Reactions

This medication may cause severe skin reactions, including Stevens-Johnson syndrome (SJS) and other serious conditions. If you experience any of the following symptoms, seek medical attention immediately:

Red, swollen, blistered, or peeling skin
Red or irritated eyes
Sores in the mouth, throat, nose, eyes, genitals, or skin
Fever
Chills
Body aches
Shortness of breath
Swollen glands

Other Side Effects

While many people may not experience side effects or may only have mild symptoms, it's essential to be aware of the following potential side effects:

Hair loss
Muscle spasms
Dizziness, drowsiness, tiredness, or weakness
Sleep disturbances
Gas
Headache
Dry skin
Watery eyes
Changes in taste
Nose or throat irritation
Back, muscle, joint, arm, or leg pain
Weight gain
Night sweats
Anxiety
Stomach pain or heartburn
* Constipation, diarrhea, nausea, vomiting, or decreased appetite

If any of these side effects bother you, do not improve, or are severe, contact your doctor for guidance on managing them.

Reporting Side Effects

If you experience any side effects, you can report them to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced.
If you are currently taking warfarin.
If you are taking any of the following medications: carbamazepine, dexamethasone, phenobarbital, phenytoin, rifabutin, rifampin, or St. John's wort.
If you are breastfeeding. Note that you should not breastfeed while taking this medication or for 1 month after your last dose.

This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health issues with your doctor and pharmacist. They will help determine if it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dosage of any medication without first consulting your doctor.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Before engaging in activities that require alertness and clear vision, such as driving, wait until you understand how this drug affects you.

Regular blood tests and other laboratory evaluations should be performed as directed by your doctor. Additionally, avoid consuming grapefruit and grapefruit juice, as they may interact with this medication. This drug can potentially suppress the bone marrow's ability to produce necessary blood cells, leading to an increased risk of bleeding problems, infections, or anemia. If you have concerns, consult your doctor.

You may be more susceptible to infections; therefore, practice good hygiene by washing your hands frequently and avoiding close contact with individuals who have infections, colds, or flu. Furthermore, this medication can increase your risk of bleeding easily. To minimize this risk, be cautious, avoid injuries, and use a soft toothbrush and an electric razor. If you have had your thyroid removed, discuss with your doctor the need for more frequent blood tests.

Before receiving any vaccinations, consult your doctor, as certain vaccines may not be effective or may increase the risk of infection when used with this medication. You may also be more prone to sunburn; thus, limit your exposure to sunlight, sunlamps, and tanning beds, and use protective measures such as sunscreen, clothing, and eyewear.

There is a risk of severe and potentially life-threatening gastrointestinal tract perforation associated with this drug. Discuss this risk with your doctor. If you are 65 years or older, use this medication with caution, as you may be more likely to experience side effects.

In some cases, this drug may affect growth in children and adolescents, and regular growth checks may be necessary. Discuss this with your doctor. This medication can cause harm to an unborn baby. A pregnancy test will be conducted before initiating treatment to confirm that you are not pregnant. If you may become pregnant, use birth control while taking this drug and for at least 2 weeks after your last dose. If you become pregnant, notify your doctor immediately.

• Strong CYP3A4 inducers (e.g., Rifampin, Phenytoin, Carbamazepine, Phenobarbital, St. John's Wort): May significantly decrease imatinib plasma concentrations, leading to loss of efficacy. Concomitant use should be avoided.
• Warfarin and other coumarin derivatives: Imatinib may increase anticoagulant effect due to CYP2C9 and CYP3A4 inhibition. Monitor INR closely and adjust anticoagulant dose.

• Strong CYP3A4 inhibitors (e.g., Ketoconazole, Itraconazole, Erythromycin, Clarithromycin, Ritonavir, Indinavir, Grapefruit juice): May increase imatinib plasma concentrations, increasing risk of adverse effects. Consider dose reduction of imatinib.
• CYP3A4 substrates with narrow therapeutic index (e.g., Cyclosporine, Tacrolimus, Sirolimus, Everolimus, Fentanyl, Alfentanil, Dihydroergotamine, Ergotamine, Pimozide, Quinidine): Imatinib may increase their plasma concentrations. Monitor and adjust dose as needed.
• CYP2D6 substrates (e.g., Metoprolol, Desipramine): Imatinib may increase their plasma concentrations. Monitor and adjust dose as needed.
• CYP2C9 substrates (e.g., Celecoxib, Diclofenac, Glipizide, Losartan, Phenytoin, Tolbutamide): Imatinib may increase their plasma concentrations. Monitor and adjust dose as needed.

• Acetaminophen: Potential for increased hepatotoxicity with chronic high-dose acetaminophen, though clinical significance is low with typical doses.

• Fatigue
• Nausea
• Vomiting
• Diarrhea
• Muscle cramps/pain
• Rash
• Fluid retention (swelling, rapid weight gain, shortness of breath)
• Unusual bleeding or bruising
• Fever or signs of infection
• Yellowing of skin or eyes (jaundice)
• Dark urine
• Abdominal pain
• Chest pain or shortness of breath (new or worsening)

Imatinib can cause fetal harm when administered to a pregnant woman. Based on animal studies and its mechanism of action, imatinib is considered teratogenic. Avoid use during pregnancy. Women of childbearing potential should be advised to use effective contraception during treatment and for at least 14 days after the last dose.

Imatinib and its active metabolite are excreted into human milk. Due to the potential for serious adverse reactions in a breastfed infant, breastfeeding is not recommended during treatment with imatinib and for at least 1 month after the last dose.

Imatinib is approved for pediatric patients with newly diagnosed Ph+ CML (chronic phase) and Ph+ ALL. Dosing is based on body surface area. Safety and efficacy in other pediatric indications are not established. Close monitoring for growth and development is recommended.

No specific dose adjustment is required based on age. However, elderly patients may be more susceptible to certain adverse effects, such as fluid retention and myelosuppression. Monitor closely for adverse reactions.

• Always take imatinib with food and a large glass of water to minimize gastrointestinal irritation and improve absorption.
• Fluid retention (edema, pleural effusion, pericardial effusion, ascites) is a common and potentially serious side effect; monitor weight and fluid status regularly.
• Myelosuppression (neutropenia, thrombocytopenia, anemia) is a dose-limiting toxicity; regular CBC monitoring is crucial.
• Hepatotoxicity can occur; monitor liver function tests regularly.
• Muscle cramps and musculoskeletal pain are common side effects, often manageable with electrolyte supplementation (e.g., magnesium, calcium) or pain relievers.
• Patients should be advised to avoid grapefruit and St. John's Wort due to significant drug interactions.
• Adherence is critical for optimal outcomes in chronic conditions like CML and GIST.

• For CML: Other BCR-ABL tyrosine kinase inhibitors such as Dasatinib, Nilotinib, Bosutinib, Ponatinib.
• For GIST: Sunitinib, Regorafenib (for advanced GIST after imatinib failure).
• For other indications, alternatives vary based on specific disease and patient characteristics.

If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it is a good idea to check with your pharmacist for more information. If you have any questions or concerns about this medication, consult with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.