Meaxin (Imatinib)

Imatinib acts on malignant cells driven by specific tyrosine‑kinase pathways.

• Chronic myeloid leukemia (CML): reduces leukemic cell proliferation and improves long‑term survival.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL): induces remission by targeting BCR‑ABL signaling.
• Gastrointestinal stromal tumor (GIST): blocks c‑KIT and PDGFR activity, leading to tumor shrinkage and disease control.

• Imatinib selectively inhibits the ATP‑binding sites of BCR‑ABL, c‑KIT and PDGFR tyrosine kinases. By preventing phosphorylation of downstream substrates, it blocks proliferative and survival signaling pathways in malignant cells, leading to cell cycle arrest and apoptosis of the targeted cancer cells.

Adverse reactions may vary in frequency and severity.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Diarrhea: watery stools, often transient.
• Edema: peripheral swelling, especially of the ankles.
• Muscle cramps: painful involuntary contractions.
• Fatigue: generalized tiredness.
• Rash: mild skin eruptions.

Serious or Rare Side Effects

• Neutropenia: marked reduction in neutrophil count, increasing infection risk.
• Thrombocytopenia: low platelet levels, leading to bleeding tendencies.
• Hepatotoxicity: elevated liver enzymes or liver injury.
• Cardiac dysfunction: left ventricular failure or reduced ejection fraction.
• Severe skin reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Pulmonary arterial hypertension: elevated pulmonary artery pressure causing dyspnea.

Patients should be monitored for specific safety concerns before and during therapy.

• Pregnancy: Category D – avoid use unless benefits outweigh risks.
• Hepatic impairment: dose adjustment may be required; monitor liver function tests.
• Cardiac monitoring: assess left ventricular function periodically.
• Drug interactions: avoid concomitant use with strong CYP3A4 inhibitors.
• Store at ambient temperature: keep in the original container, protect from moisture and light.

Imatinib can interact with several medicines, altering its efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase imatinib plasma levels.
• Strong CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce therapeutic exposure.
• Concomitant use with other tyrosine‑kinase inhibitors: risk of additive toxicity.

Moderate Interactions (Monitor Closely)

• Moderate CYP3A4 inhibitors (e.g., erythromycin, fluconazole): may modestly raise concentrations.
• Warfarin: imatinib can enhance anticoagulant effect; monitor INR.
• Diuretics (e.g., furosemide): may increase risk of electrolyte disturbances.