Imatinib Zentiva (Imatinib)

Imatinib acts on the BCR‑ABL tyrosine kinase pathway, providing targeted therapy for specific hematologic and solid tumors.

• Chronic myeloid leukemia (CML): reduces malignant cell proliferation and improves survival in adult patients.
• Gastrointestinal stromal tumor (GIST): inhibits tumor growth in patients with KIT or PDGFRA mutations.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL): contributes to disease control when used in combination regimens.

• Imatinib selectively binds to the ATP‑binding pocket of the BCR‑ABL fusion protein and related kinases such as c‑KIT and PDGFRA. This occupancy blocks phosphorylation of downstream signaling molecules, halting pathways that drive uncontrolled cell division and survival. The resulting inhibition leads to apoptosis of malignant cells and reduces tumor angiogenesis.

Imatinib may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Edema: peripheral swelling, often in the lower extremities.
• Muscle cramps: intermittent painful contractions, usually in the limbs.
• Fatigue: generalized tiredness affecting daily activities.

Serious or Rare Side Effects

• Neutropenia: significant drop in white blood cells, increasing infection risk.
• Hepatotoxicity: elevated liver enzymes or liver injury requiring monitoring.
• Cardiac failure: signs of reduced cardiac function, especially in patients with pre‑existing heart disease.

Before initiating therapy, clinicians should assess baseline organ function and consider potential risks.

• Liver function monitoring: assess hepatic enzymes before and during therapy.
• Hematologic assessment: perform regular complete blood counts to detect neutropenia or anemia.
• Cardiac evaluation: monitor for signs of heart failure, especially in patients with pre‑existing cardiac disease.
• Pregnancy and lactation: avoid use unless benefits outweigh potential risks; discuss with specialist.
• Drug interactions: review concomitant medications for CYP3A4 inhibitors or inducers.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and light.

Imatinib's metabolism involves CYP3A4, making certain co‑medications clinically important.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): may increase imatinib plasma levels and toxicity.
• Azole antifungals (e.g., voriconazole): similar risk of elevated exposure.
• St. John’s wort: may reduce efficacy by inducing metabolism.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, carbamazepine): may lower drug concentrations.
• Anticoagulants (e.g., warfarin): may require INR monitoring.
• Diuretics (e.g., furosemide): may exacerbate fluid retention; monitor electrolytes.