Levin 400mg Tablet contains Imatinib mesylate, a tyrosine kinase inhibitor used primarily in the treatment of certain types of cancer, including chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GISTs). Imatinib mesylate functions by selectively inhibiting the BCR-ABL tyrosine kinase enzyme, which is produced by the Philadelphia chromosome abnormality in CML, thereby preventing the proliferation of malignant cells. Additionally, it targets other tyrosine kinases such as c-KIT and PDGF receptors, contributing to its efficacy in GISTs. Levin 400mg is indicated for adult patients diagnosed with Philadelphia chromosome-positive CML in chronic, accelerated, or blast crisis phases, as well as for unresectable and/or metastatic malignant GISTs expressing the c-KIT protein. The tablet is administered orally, with dosage and duration tailored according to the specific condition and patient response. Common adverse effects include nausea, edema, muscle cramps, rash, and fatigue, while serious adverse reactions may involve myelosuppression, hepatotoxicity, and cardiotoxicity. Regular monitoring of blood counts, liver function tests, and cardiac status is recommended during therapy. Levin 400mg should be prescribed and used under strict medical supervision to optimize therapeutic outcomes and minimize potential risks.