Fluid retention and edema: Imatinib is often associated with edema and, occasionally, serious fluid retention. Weigh and monitor patients regularly for signs and symptoms of fluid retention. Carefully investigate an unexpected rapid weight gain and provide appropriate treatment. The probability of edema was increased with higher imatinib dose and age older than 65 years in the CML studies. Severe superficial edema was reported in 1.5% of newly diagnosed patients with CML taking imatinib and in 2% to 6% of other adults with CML taking imatinib. In addition, other severe fluid retention (eg, ascites, pericardial effusion, pleural effusion, pulmonary edema) reactions were reported in 1.3% of newly diagnosed patients with CML taking imatinib and in 2% to 6% of other adults with CML taking imatinib. Severe fluid retention was reported in 9% to 13.1% of patients taking imatinib for GI stromal tumor.
Hematologic toxicity: Treatment with imatinib is often associated with anemia, neutropenia, or thrombocytopenia. Perform complete blood cell counts (CBCs) weekly for the first month, biweekly for the second month, and periodically thereafter as clinically indicated (eg, every 2 to 3 months) . The occurrence of these cytopenias is dependent on the stage of disease and is more frequent in patients with accelerated phase CML or blast crisis than in patients with chronic-phase CML. In pediatric patients with CML, the most frequent toxicities observed were grade 3 or 4 cytopenias, including neutropenia, thrombocytopenia, and anemia. These generally occur within the first several months of therapy.
Cardiovascular effects: Severe congestive heart failure and left ventricular dysfunction have occasionally been reported in patients taking imatinib. Most of the patients with reported cardiac reactions have had other comorbidities and risk factors, including advanced age and previous medical history of cardiac disease. In an international, randomized, phase 3 study in 1106 patients with newly diagnosed Ph+ CML in chronic phase, severe cardiac failure and left ventricular dysfunction were observed in 0.7% of patients taking imatinib compared with 0.9% of patients taking interferon-alpha + cytarabine. Carefully monitor patients with cardiac disease or risk factors for cardiac failure and evaluate and treat any patient with signs or symptoms consistent with cardiac failure.
Hepatotoxicity: Hepatotoxicity, occasionally severe, may occur with imatinib. Cases of fetal liver failure and severe liver injury requiring liver transplants have been reported with both short-term and long-term uses of imatinib. Monitor liver function (transaminases, bilirubin, and alkaline phosphatase) before initiation of treatment and monthly thereafter, or as clinically indicated. Manage laboratory abnormalities with interruption and/or dose reduction of the treatment with imatinib. When imatinib is combined with chemotherapy, liver toxicity in the form of transaminase elevation and hyperbilirubinemia has been observed. Additionally, there have been reports of acute liver failure. Monitoring of hepatic function is recommended.
Hemorrhage: In the newly diagnosed CML trial, 1.8% of patients had grade 3/4 hemorrhage. In the phase 3 unresectable or metastatic GI stromal tumor studies, 12.9% of patients reported grade 3/4 hemorrhage at any site. In the phase 2 unresectable or metastatic GI stromal tumor study, 5% of patients had a total of 8 common toxicity criteria (CTC) grade 3/4 hemorrhages: GI (3 patients), intratumoral (3 patients), or both (1 patient). GI tumor sites may have been the source of GI hemorrhages.
GI effects: Imatinib is sometimes associated with GI irritation. Instruct patients to take imatinib with food and a large glass of water to minimize this problem. There have been rare reported, including fatalities, of GI perforation.
Hypereosinophilic cardiac toxicity: In patients with hypereosinophilic syndrome and cardiac involvement, cases of cardiogenic shock/left ventricular dysfunction have been associated with the initiation of imatinib therapy. The condition was reported to be reversible with the administration of systemic steroids, circulatory support measures, and temporary withholding of imatinib. Myelodysplastic/ myeloproliferative diseases and systemic mastocytosis may be associated with high eosinophil levels. Therefore, consider performing an echocardiogram and determining serum troponin in patients with hypereosinophilic syndrome/chronic eosinophilic leukemia and in patients with myelodysplastic/myeloproliferative diseases or aggressive systemic mastocytosis associated with high eosinophilic levels. If either is abnormal, consider the prophylactic use of systemic steroids (1 to 2 mg/kg) for 1 to 2 weeks concomitantly with imatinib at the initiation of therapy.
Dermatologic effects: Bullous dermatologic reactions, including erythema multiforme and Stevens-Johnson syndrome, have been reported with use of imatinib. In some cases of bullous dermatologic reactions, including erythema multiforme and Stevens-Johnson syndrome reported during post-marketing surveillance, a recurrent dermatologic reaction was observed upon rechallenge. Several foreign postmarketing reports have described cases in which patients tolerated the reintroduction of imatinib therapy after resolution or improvement of the bullous reaction. In these instances, imatinib was resumed at a dose lower than that at which the reaction occurred, and some patients also received concomitant treatment with corticosteroids or antihistamines.
Hypothyroidism: Clinical cases of hypothyroidism have been reported in thyroidectomy patients undergoing levothyroxine replacement during treatment with imatinib. Closely monitor thyroid- stimulating hormone levels in such patients.
Tumor lysis syndrome: Cases of tumor lysis syndrome, including fatal cases, have been reported in patients with CML, GI stromal tumor, ALL, and eosinophilic leukemia receiving imatinib. The patients at risk of tumor lysis syndrome are those with tumors having a high proliferative rate or high tumor burden prior to treatment. Monitor these patients closely and take appropriate cautions.
Renal function impairment: Use with caution in patients with severe renal impairment. Dosage reductions are necessary for patients with moderate and severe renal impairment.
Hepatic function impairment: A reduced dose is recommended in patients with severe hepatic impairment.
Use in Children: Imatinib safety and efficacy have been demonstrated in children with newly diagnosed Ph+ chronic-phase CML. There are no data in children younger than 2 years.
Growth retardation has been reported in children and preadolescents receiving imatinib. The long-term effects of prolonged treatment with imatinib on growth in children are unknown. Therefore, close monitoring of growth in children under imatinib treatment is recommended.
Use in the Elderly: The incidence of edema was increased with age older than 65 years in the CML and GI stromal tumor studies.