Imatinib: Uses, Dosage, Side Effects & Cost Explained

Summary of Key Points

Imatinib, also known as Imatinib mesylate, is a prescription medication primarily used to treat certain types of cancer, including chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST). It works by targeting and inhibiting the growth of cancer cells. This medication is taken orally, usually once or twice daily, and comes in tablet form. It is essential to consult your healthcare provider before starting or adjusting your dosage. Our telemedicine providers are available to support you in managing your treatment effectively.

Names of the Medication

US Brand Name: Gleevec

Generic Name: Imatinib

The generic name, Imatinib, refers to the active ingredient in the medication, while the brand name, Gleevec, is the name given by the manufacturer. Throughout this article, the generic name is included in parentheses to ensure clarity.

Pharmacologic Category

Imatinib belongs to a class of medications known as tyrosine kinase inhibitors, which are commonly used in targeted cancer therapies to block specific enzymes that promote cancer cell growth.

Imatinib Dosage Guidelines

The appropriate dosage of Imatinib depends on the specific condition being treated. Always follow your doctor’s instructions and consult them before making any changes to your prescribed dose. For additional support, you can schedule a telemedicine appointment with one of our providers.

Imatinib for Chronic Myeloid Leukemia (CML)

Initial Dose: 400 mg once daily for chronic-phase CML. For accelerated-phase CML or blast crisis, the dose may be increased to 600 mg once daily.

Duration: Treatment is typically long-term and continues as long as the patient shows a positive response to therapy.

Imatinib for Gastrointestinal Stromal Tumors (GIST)

Initial Dose: 400 mg once daily.

Duration: Treatment continues as long as the tumor responds to therapy or until disease progression occurs.

Imatinib for Acute Lymphoblastic Leukemia (ALL)

Initial Dose: 600 mg once daily for Philadelphia chromosome-positive (Ph+) ALL.

Duration: Treatment is maintained as long as the patient continues to respond to therapy.

Imatinib for Dermatofibrosarcoma Protuberans (DFSP)

Initial Dose: 800 mg daily, divided into two doses of 400 mg each.

Duration: The length of treatment depends on the patient’s response to therapy.

Imatinib for Myelodysplastic Syndromes (MDS) and Myeloproliferative Disorders (MPD)

Initial Dose: 400 mg once daily.

Duration: Treatment is generally long-term and tailored to the patient’s response.

Imatinib for Hypereosinophilic Syndrome (HES) and Chronic Eosinophilic Leukemia (CEL)

Initial Dose: 100 mg once daily, with the possibility of increasing to 400 mg depending on the patient’s response.

Duration: Treatment is continued as long as the patient benefits from therapy.

Imatinib for Systemic Mastocytosis

Initial Dose: 100 mg to 400 mg once daily, depending on specific genetic mutations.

Duration: The duration of treatment is based on the patient’s response to therapy.

Imatinib for Ph+ Acute Lymphoblastic Leukemia (Ph+ ALL)

Initial Dose: 600 mg once daily.

Duration: Treatment is continued as long as the patient demonstrates a positive response to therapy.

Dosage Forms and Strengths

Imatinib is available in the following tablet strengths:

1. 100 mg tablets
2. 400 mg tablets

Administration Instructions for Imatinib

To minimize the risk of stomach upset, Imatinib should be taken with a meal and a large glass of water. Swallow the tablets whole; do not crush or chew them. If swallowing is difficult, the tablet can be dissolved in water or apple juice. Always follow your healthcare provider’s instructions for taking this medication. If you have any questions or concerns, feel free to reach out to us through telemedicine for assistance.

Contraindications for Imatinib

A contraindication refers to a specific condition or circumstance in which using a medication could pose a risk to the patient. Identifying contraindications is a critical step before starting any new treatment. Below are the key contraindications for taking Imatinib:

Allergic reaction to Imatinib: If you have ever experienced an allergic reaction to Imatinib mesylate or any of its ingredients, you should avoid this medication. Signs of an allergic reaction may include rash, itching, swelling, or difficulty breathing, which, in severe cases, can become life-threatening.

Liver disease:Imatinib is processed by the liver. If you have severe liver disease, your body may struggle to metabolize the medication properly, potentially leading to toxic levels in your system.

Kidney disease: Since Imatinib mesylate is also eliminated through the kidneys, severe kidney disease can impair the body’s ability to clear the drug, increasing the likelihood of side effects.

Heart failure or heart disease:Imatinib can cause fluid retention, which may exacerbate heart failure or other cardiac conditions. If you have a history of heart problems, this medication may not be appropriate for you.

Drug-to-Drug Interactions with Imatinib

Imatinib can interact with other medications, potentially increasing side effects or reducing the effectiveness of one or both drugs. Below are some medications known to interact with Imatinib mesylate:

1. Warfarin (Coumadin):Imatinib can amplify the effects of warfarin, a blood thinner, which may heighten the risk of bleeding.
2. Ketoconazole (Nizoral): This antifungal medication can increase Imatinib levels in your body, potentially leading to more pronounced side effects.
3. Carbamazepine (Tegretol): Commonly used to treat seizures, this medication can reduce the effectiveness of Imatinib by speeding up its breakdown in the liver.
4. Simvastatin (Zocor):Imatinib may elevate simvastatin levels, increasing the risk of muscle damage or other complications.
5. Acetaminophen (Tylenol): Taking high doses of acetaminophen alongside Imatinib may raise the risk of liver damage.

Imatinib and Pregnancy

Is It Safe to Take Imatinib During Pregnancy?

Imatinib is generally not recommended during pregnancy, as it may harm the developing baby. Research has shown that Imatinib mesylate can cause birth defects and other complications. If you are pregnant or planning to become pregnant, it is crucial to consult your healthcare provider to explore alternative treatment options. If you are already taking Imatinib and discover you are pregnant, contact your healthcare provider immediately to discuss the best course of action. Our telemedicine providers are available to support you in making informed decisions for both your health and your baby’s well-being.

Imatinib While Breastfeeding

Is It Safe to Take Imatinib While Breastfeeding?

Imatinib is not recommended while breastfeeding, as it can pass into breast milk and may harm your baby. If you are currently breastfeeding or planning to do so, speak with your healthcare provider about alternative treatments. You may need to either discontinue breastfeeding or switch to a different medication. Our telemedicine providers can help you find the safest and most effective solution for both you and your child.

Estimated Cost of Imatinib

The cost of a 30-day supply of Imatinib without insurance can vary depending on the pharmacy and dosage. With a GoodRx coupon, the estimated price for a 30-day supply of Imatinib mesylate typically ranges from $9,000 to $10,000. To reduce costs, check with your pharmacy and explore available coupon options. If affordability is a concern, our telemedicine providers can guide you through financial assistance programs or other resources to help manage the expense.

Possible Alternatives to Imatinib

Depending on the condition being treated, alternative therapies or lifestyle adjustments may help manage your disease. It is essential to consult your healthcare provider before making any changes to your treatment plan. Below are some potential alternatives for conditions commonly treated with Imatinib:

Chronic Myeloid Leukemia (CML)

For chronic myeloid leukemia, other tyrosine kinase inhibitors, such as dasatinib (Sprycel) or nilotinib (Tasigna), may be considered as alternatives to Imatinib. In certain cases, stem cell transplantation could also be an option, depending on the patient’s overall health and disease stage.

Gastrointestinal Stromal Tumors (GIST)

If Imatinib proves ineffective or causes significant side effects, alternative treatments for gastrointestinal stromal tumors include sunitinib (Sutent) or regorafenib (Stivarga). Surgery may also be an option, particularly if the tumor’s size and location make it operable.

Acute Lymphoblastic Leukemia (ALL)

Treatment for acute lymphoblastic leukemia may involve chemotherapy, radiation therapy, or other targeted therapies such as dasatinib (Sprycel). These options are carefully tailored to the patient’s specific needs, taking into account the progression and characteristics of the disease.

Dermatofibrosarcoma Protuberans (DFSP)

Surgery is typically the primary treatment for dermatofibrosarcoma protuberans. If surgery is not a viable option, radiation therapy may be considered as an alternative to Imatinib.

Myelodysplastic Syndromes (MDS)

For myelodysplastic syndromes, treatment options may include supportive care, chemotherapy, or stem cell transplantation. In some cases, lenalidomide (Revlimid) can serve as an alternative therapy, particularly for patients with specific genetic abnormalities.

Hypereosinophilia

Patients with hypereosinophilia may explore corticosteroids or other immunosuppressive therapies as alternatives to Imatinib. These treatments are often used to manage symptoms and reduce elevated eosinophil levels effectively.

Systemic Mastocytosis

For systemic mastocytosis, alternative treatments may include antihistamines, corticosteroids, or other tyrosine kinase inhibitors such as midostaurin (Rydapt). These therapies aim to alleviate symptoms and improve the patient’s quality of life.

Chronic Eosinophilic Leukemia

Alternatives for chronic eosinophilic leukemia may involve corticosteroids, hydroxyurea, or other targeted therapies, depending on the specific genetic mutations associated with the condition.

Ph+ Acute Lymphoblastic Leukemia

For Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), other tyrosine kinase inhibitors, such as dasatinib (Sprycel) or ponatinib (Iclusig), may be used as alternatives to Imatinib. These therapies are often selected based on the patient’s response to treatment and overall health.

Myeloproliferative Disorders

Treatment options for myeloproliferative disorders may include hydroxyurea, interferon, or other targeted therapies, depending on the specific disorder and its progression. Your healthcare provider will determine the most appropriate approach based on your individual condition.

Always consult your healthcare provider before making any changes to your treatment plan. If you need additional guidance, our telemedicine providers are available to discuss your options and help you make informed decisions about your care.

Recent Updates on Imatinib Research

Recent studies continue to assess the long-term effectiveness and safety of Imatinib, particularly in patients with chronic myeloid leukemia (CML). Research indicates that some patients who achieve deep molecular remission may be able to discontinue Imatinib under close medical supervision. However, this approach is not yet considered standard practice and requires careful monitoring.

Additionally, ongoing research is exploring the use of Imatinib in combination with other therapies to improve outcomes in various cancers, including gastrointestinal stromal tumors (GIST) and acute lymphoblastic leukemia (ALL). These studies aim to enhance the effectiveness of cancer treatments and broaden the potential applications of Imatinib.

Researchers are also investigating the potential of Imatinib to treat conditions beyond cancer, such as pulmonary arterial hypertension (PAH) and fibrotic diseases. While these uses remain experimental, they highlight the versatility of this tyrosine kinase inhibitor. If you are interested in learning more about the latest research or clinical trials involving Imatinib, our telemedicine providers can assist you in exploring your options.

James Kingsley

Learn More