Glivec (Imatinib)

Glivec (imatinib) is indicated for the treatment of specific hematologic and solid tumors that are driven by abnormal tyrosine‑kinase activity.

• Chronic myeloid leukemia (CML) in chronic, accelerated, or blast phase.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL) when appropriate.
• Gastrointestinal stromal tumor (GIST) that is unresectable or metastatic and expresses KIT or PDGFRA mutations.
• Certain other KIT‑positive tumors as determined by a physician.

Adverse reactions to Glivec are documented across clinical trials and real‑world use; they range from mild, frequently observed events to rare but potentially life‑threatening conditions.

Common

• Nausea, vomiting, or decreased appetite, often occurring early in therapy.
• Diarrhea or constipation, which may require dietary adjustments.
• Fatigue, generalized weakness, or muscle cramps that can affect daily activities.

Serious

• Hepatotoxicity presenting as elevated liver enzymes or clinically significant liver injury.
• Cardiac dysfunction, including reduced left‑ventricular ejection fraction or overt heart failure.
• Hematologic toxicity such as severe neutropenia, thrombocytopenia, or anemia requiring close monitoring.

Before initiating Glivec, clinicians assess several patient‑specific factors to minimize risks and ensure appropriate monitoring.

• Baseline liver function tests and periodic monitoring during treatment.
• Cardiac evaluation, especially in patients with pre‑existing heart disease.
• Complete blood count before start and regularly to detect cytopenias.
• Assessment of pregnancy status; use only if potential benefit justifies potential risk.
• Review of concomitant medications that may affect imatinib metabolism.
• Monitoring for signs of fluid retention or edema.
• Consider dose adjustments in patients with severe renal impairment.

Glivec is metabolized primarily by the CYP3A4 enzyme, so co‑administration with certain drugs can alter its exposure.

Avoid

• Strong CYP3A4 inducers such as rifampin, carbamazepine, or phenytoin, which may reduce efficacy.
• Potent CYP3A4 inhibitors like ketoconazole, itraconazole, or clarithromycin, which may increase toxicity.

Use with caution

• Antacids or proton‑pump inhibitors that raise gastric pH, potentially affecting absorption.
• Concomitant use of other myelosuppressive agents, increasing risk of blood‑cell disorders.
• Drugs that prolong the QT interval, as imatinib may have additive cardiac effects.
• Warfarin or other anticoagulants, due to possible altered bleeding risk.
• Medications that are substrates of CYP3A4, which may have altered plasma levels.