Imatinib Krka D.D. (Imatinib)

Imatinib is a targeted therapy that interferes with the BCR‑ABL tyrosine‑kinase pathway and related oncogenic drivers.

• Chronic myeloid leukemia (CML): provides disease control by inhibiting BCR‑ABL signaling.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL): facilitates remission through kinase blockade.
• Gastrointestinal stromal tumor (GIST): induces tumor shrinkage by targeting KIT/PDGFRA mutations.
• Other KIT or PDGFRA driven tumors: helps stabilize disease progression.

• Imatinib selectively binds to the ATP‑binding pocket of BCR‑ABL, KIT, and PDGFRA tyrosine kinases, preventing phosphorylation of downstream substrates. This inhibition blocks proliferative and survival signaling pathways in malignant cells, leading to reduced tumor growth and induction of apoptosis in kinase‑dependent cancers.

Adverse reactions may vary in frequency and severity.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Edema: peripheral swelling, often in the ankles.
• Fatigue: generalized tiredness.
• Muscle cramps: occasional painful contractions.
• Diarrhea: loose stools.
• Rash: mild skin eruptions.

Serious or Rare Side Effects

• Hepatotoxicity: elevated liver enzymes or liver injury.
• Cardiotoxicity: reduced left‑ventricular ejection fraction.
• Severe neutropenia: marked decrease in white blood cells.
• Hemorrhagic events: unusual bleeding or bruising.

Patients should be monitored for organ function and potential toxicities.

• Baseline labs: obtain liver, renal, and hematologic parameters before starting therapy.
• Cardiac assessment: evaluate cardiac function in patients with pre‑existing heart disease.
• Drug interactions: review concomitant medications for CYP3A4 substrates or inhibitors.
• Pregnancy and lactation: avoid use unless benefits clearly outweigh risks.
• Storage: Store below 25°C: keep in the original container, protect from moisture and light.

Imatinib may alter the pharmacokinetics of several co‑administered agents.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase imatinib exposure.
• Strong CYP3A4 inducers (e.g., rifampicin, carbamazepine): may reduce therapeutic levels.

Moderate Interactions (Monitor Closely)

• Acid‑reducing agents (e.g., proton pump inhibitors, antacids): can affect absorption.
• Warfarin: may enhance anticoagulant effect, requiring INR monitoring.
• CYP2C8 substrates (e.g., repaglinide): potential increased plasma concentrations.
• Vaccines: live attenuated vaccines should be avoided during treatment.