Imatinib Krka D.D. (Imatinib)

Imatinib acts on malignant cells driven by BCR‑ABL and related kinases, providing targeted therapy for several hematologic and solid tumours.

• Chronic myeloid leukemia (CML): suppresses disease progression by inhibiting BCR‑ABL kinase activity.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL): induces remission through blockade of oncogenic signaling.
• Gastrointestinal stromal tumor (GIST): reduces tumor growth by targeting KIT and PDGFRA kinases.
• Other BCR‑ABL positive neoplasms: offers disease control where BCR‑ABL drives malignancy.

• Imatinib selectively binds to the ATP‑binding site of BCR‑ABL, KIT, and PDGFRA tyrosine kinases, stabilising them in an inactive conformation. This prevents phosphorylation of downstream substrates, halting proliferative signaling pathways and inducing apoptosis in malignant cells that depend on these kinases for growth and survival.

Adverse reactions may vary in frequency and severity.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Edema: peripheral swelling, often in the ankles.
• Muscle cramps: transient skeletal muscle discomfort.
• Fatigue: generalized tiredness.
• Rash: mild skin erythema.
• Diarrhea: loose stools.

Serious or Rare Side Effects

• Neutropenia: marked reduction in white blood cells.
• Hepatotoxicity: elevated liver enzymes or liver injury.
• Cardiac failure: reduced cardiac output or congestive signs.
• Severe hemorrhage: bleeding complications.
• Interstitial lung disease: pulmonary inflammation.
• Anaphylaxis: rare hypersensitivity reaction.

Patients should be monitored for safety and efficacy throughout therapy.

• Blood counts: perform regular complete blood count monitoring.
• Liver function: assess hepatic enzymes before and during treatment.
• Cardiac assessment: evaluate cardiac status in patients with pre‑existing heart disease.
• Drug interactions: review concomitant medications for CYP3A4 modulators.
• Pregnancy and lactation: avoid use unless benefits outweigh potential risks.
• Store at ambient temperature: keep below 25 °C, in the original container, protected from moisture and light.

Imatinib may interact with several co‑administered medicines, requiring clinical vigilance.

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.
• Antacids containing aluminum or magnesium: can impair absorption.

Moderate Interactions (Monitor Closely)

• Warfarin: may enhance anticoagulant effect, monitor INR.
• Digoxin: possible increase in serum digoxin concentrations.
• CYP2C8 substrates (e.g., paclitaxel): may require dose adjustment.
• Proton pump inhibitors: may modestly affect bioavailability.
• Vaccines: live vaccines should be avoided during treatment.