Glivec (Imatinib)

Glivec (imatinib) is indicated for several malignancies where abnormal tyrosine‑kinase activity drives disease progression.

• Chronic myeloid leukemia (CML) across chronic, accelerated, and blast phases, as first‑line therapy.
• Philadelphia chromosome‑positive acute lymphoblastic leukemia (Ph+ ALL) in adult patients.
• Gastrointestinal stromal tumor (GIST) that is unresectable, metastatic, or recurrent after surgery.
• Dermatofibrosarcoma protuberans (DFSP) as adjuvant treatment following complete surgical excision.
• Systemic mastocytosis with symptomatic disease, including organ involvement.
• Additional investigational indications evaluated in clinical trials.

The safety profile of Glivec includes a range of adverse events that vary in frequency and severity.

Common

• Nausea, vomiting, or loss of appetite, often mild to moderate.
• Diarrhea or abdominal discomfort, which may be intermittent.
• Edema, particularly peripheral swelling of the ankles or hands.
• Fatigue or generalized weakness that can affect daily activities.
• Skin rash or mild pruritus, sometimes accompanied by dry skin.

Serious

• Severe neutropenia or leukopenia, which can increase the risk of serious infections.
• Hepatotoxicity, indicated by markedly elevated liver enzymes or jaundice.
• Cardiac dysfunction such as congestive heart failure, though it occurs rarely.

When prescribing Glivec, clinicians consider several precautionary measures to minimize risks and optimize therapy.

• Baseline and periodic complete blood counts to monitor for cytopenias.
• Liver function tests before initiation and regularly during treatment.
• Assessment of cardiac function in patients with pre‑existing heart disease.
• Evaluation of pregnancy status; drug may pose risks to the fetus.
• Monitoring for signs of fluid retention or edema, especially in the lower extremities.
• Adjustments may be needed in patients with severe renal impairment.
• Caution in elderly patients due to increased susceptibility to adverse effects.

Glivec can interact with other medicines, altering its effectiveness or increasing toxicity.

Avoid

• Strong CYP3A4 inducers such as rifampin, carbamazepine, or phenytoin, which may reduce imatinib levels.
• Concomitant use with potent CYP3A4 inhibitors like ketoconazole or clarithromycin, which can raise drug concentrations.

Use with caution

• Antacids or proton‑pump inhibitors that may affect gastric pH and absorption.
• Warfarin, as imatinib may enhance anticoagulant effects and require INR monitoring.
• Vaccines, particularly live attenuated vaccines, due to potential immunosuppression.
• Herbal supplements containing St. John’s wort, a CYP3A4 inducer.