Itivas (Imatinib)

Imatinib is used to target specific tyrosine‑kinase driven malignancies.

• Chronic myeloid leukemia (CML): reduces disease burden and improves survival by inhibiting BCR‑ABL signaling.
• Gastrointestinal stromal tumor (GIST): controls tumor growth in patients with KIT or PDGFRA mutations.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL): achieves remission by blocking proliferative kinase pathways.

• Imatinib selectively inhibits the BCR‑ABL tyrosine kinase as well as related kinases such as KIT and PDGFRA. By binding to the ATP‑binding site of these enzymes, it prevents phosphorylation of downstream substrates, thereby blocking proliferative and survival signaling in malignant cells. This targeted inhibition leads to apoptosis and reduced tumor cell replication in diseases driven by these kinases.

Imatinib may cause a range of adverse reactions, which are classified by frequency and severity.

Common Side Effects

• Nausea: mild gastrointestinal upset.
• Diarrhea: watery stools, often transient.
• Fatigue: general tiredness or lack of energy.
• Edema: peripheral swelling, especially of the ankles.

Serious or Rare Side Effects

• Hepatotoxicity: elevated liver enzymes or liver injury.
• Severe neutropenia: marked reduction in neutrophils increasing infection risk.
• Cardiotoxicity: decreased left ventricular ejection fraction or heart failure.
• Pancreatitis: inflammation of the pancreas with abdominal pain.
• Hypersensitivity reactions: rash, Stevens‑Johnson syndrome, or anaphylaxis.

When prescribing Imatinib, clinicians should observe several precautionary measures to ensure patient safety.

• Monitor blood counts: regular CBC testing to detect cytopenias.
• Assess liver function: periodic LFTs to identify hepatotoxicity.
• Evaluate cardiac status: baseline and periodic echocardiograms for heart function.
• Avoid use in patients with known hypersensitivity to imatinib or its excipients.
• Store at below 25°C: keep in original packaging, protect from moisture and light.

Imatinib interacts with several drugs that can alter its plasma concentration or increase toxicity.

Major Interactions (Avoid)

• CYP3A4 strong inhibitors (e.g., ketoconazole, clarithromycin): can raise imatinib levels and risk toxicity.
• CYP3A4 inducers (e.g., rifampicin, carbamazepine): can lower imatinib exposure and reduce efficacy.

Moderate Interactions (Monitor Closely)

• Acid‑reducing agents (e.g., proton pump inhibitors, antacids): may decrease absorption, monitor therapeutic response.
• Concomitant anticoagulants (e.g., warfarin): imatinib may enhance anticoagulant effect, check INR.
• Live attenuated vaccines: potential reduced efficacy, consider timing.