warnings and cautions
5 WARNINGS AND PRECAUTIONS Edema and severe fluid retention have occurred. Weigh patients regularly and manage unexpected rapid weight gain by drug interruption and diuretics. ( 5.1 , 6.1 ) Cytopenias, particularly anemia, neutropenia, and thrombocytopenia, have occurred. Manage with dose reduction, dose interruption, or discontinuation of treatment. Perform complete blood counts weekly for the first month, biweekly for the second month, and periodically thereafter. ( 5.2 ) Severe congestive heart failure and left ventricular dysfunction have been reported, particularly in patients with comorbidities and risk factors. Monitor and treat patients with cardiac disease or risk factors for cardiac failure. ( 5.3) Severe hepatotoxicity, including fatalities may occur. Assess liver function before initiation of treatment and monthly thereafter or as clinically indicated. Monitor liver function when combined with chemotherapy known to be associated with liver dysfunction. ( 5.4 ) Grade 3/4 hemorrhage has been reported in clinical studies in patients with newly diagnosed CML and with GIST. GI tumor sites may be the source of GI bleeds in GIST. ( 5.5 ) Gastrointestinal (GI) perforations, some fatal, have been reported. ( 5.6 ) Cardiogenic shock/left ventricular dysfunction has been associated with the initiation of imatinib mesylate tablets in patients with conditions associated with high eosinophil levels (e.g., HES, MDS/MPD, and ASM). ( 5.7 ) Bullous dermatologic reactions (e.g., erythema multiforme and Stevens-Johnson syndrome) have been reported with the use of imatinib mesylate tablets. ( 5.8 ) Hypothyroidism has been reported in thyroidectomy patients undergoing levothyroxine replacement. Closely monitor TSH levels in such patients. ( 5.9 ) Fetal harm can occur when administered to a pregnant woman. Apprise women of the potential harm to the fetus, and to use effective contraception. ( 5.10 , 8.1 ) Growth retardation occurring in children and pre-adolescents receiving imatinib mesylate tablets has been reported. Close monitoring of growth in children under imatinib mesylate tablets treatment is recommended. ( 5.11 , 6.2 ) Tumor Lysis Syndrome. Close monitoring is recommended. ( 5.12 ) Reports of motor vehicle accidents have been received in patients receiving imatinib mesylate tablets. Caution patients about driving a car or operating machinery. ( 5.13 ) Renal Toxicity. A decline in renal function may occur in patients receiving imatinib mesylate tablets. Evaluate renal function at baseline and during therapy, with attention to risk factors for renal dysfunction. ( 5.14 ) 5.1 Fluid Retention and Edema Imatinib mesylate tablets are often associated with edema and occasionally serious fluid retention [see Adverse Reactions (6.1)] . Weigh and monitor patients regularly for signs and symptoms of fluid retention. Investigate unexpected rapid weight gain carefully and provide appropriate treatment. The probability of edema was increased with higher imatinib mesylate tablets dose and age greater than 65 years in the CML studies. Severe superficial edema was reported in 1.5% of newly diagnosed CML patients taking imatinib mesylate tablets, and in 2% to 6% of other adult CML patients taking imatinib mesylate tablets. In addition, other severe fluid retention (e.g., pleural effusion, pericardial effusion, pulmonary edema, and ascites) reactions were reported in 1.3% of newly diagnosed CML patients taking imatinib mesylate tablets, and in 2% to 6% of other adult CML patients taking imatinib mesylate tablets. Severe fluid retention was reported in 9% to 13.1% of patients taking imatinib mesylate tablets for GIST [see Adverse Reactions (6.1)] . In a randomized trial in patients with newly diagnosed Ph+ CML in chronic phase comparing imatinib mesylate tablets and nilotinib, severe (Grade 3 or 4) fluid retention occurred in 2.5% of patients receiving imatinib mesylate tablets and in 3.9% of patients receiving nilotinib 300 mg twice daily. Effusions (including pleural effusion, pericardial effusion, ascites) or pulmonary edema were observed in 2.1% (none were Grade 3 or 4) of patients in the imatinib mesylate tablets arm and 2.2% (0.7% Grade 3 or 4) of patients in the nilotinib 300 mg twice daily arm. 5.2 Hematologic Toxicity Treatment with imatinib mesylate tablets is associated with anemia, neutropenia, and thrombocytopenia. Perform complete blood counts weekly for the first month, biweekly for the second month, and periodically thereafter as clinically indicated (for example, every 2 to 3 months). In CML, 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 CML patients 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 [see Dosage and Administration (2.14)] . 5.3 Congestive Heart Failure and Left Ventricular Dysfunction Congestive heart failure and left ventricular dysfunction have been reported in patients taking imatinib mesylate tablets. Cardiac adverse reactions were more frequent in patients with advanced age or co-morbidities, including previous medical history of cardiac disease. In an international randomized Phase 3 study in 1,106 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 mesylate tablets compared to 0.9% of patients taking IFN + Ara-C. In another randomized trial with newly diagnosed Ph+ CML patients in chronic phase that compared imatinib mesylate tablets and nilotinib, cardiac failure was observed in 1.1% of patients in the imatinib mesylate tablets arm and 2.2% of patients in the nilotinib 300 mg twice daily arm and severe (Grade 3 or 4) cardiac failure occurred in 0.7% of patients in each group. Carefully monitor patients with cardiac disease or risk factors for cardiac or history of renal failure. Evaluate and treat any patient with signs or symptoms consistent with cardiac or renal failure. 5.4 Hepatotoxicity Hepatotoxicity, occasionally severe, may occur with imatinib mesylate tablets [see Adverse Reactions (6.1)] . Cases of fatal liver failure and severe liver injury requiring liver transplants have been reported with both short-term and long-term use of imatinib mesylate tablets. Monitor liver function (transaminases, bilirubin, and alkaline phosphatase) before initiation of treatment and monthly, or as clinically indicated. Manage laboratory abnormalities with imatinib mesylate tablets interruption and/or dose reduction [see Dosage and Administration (2.13)] . When imatinib mesylate tablets are 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. 5.5 Hemorrhage In a trial of imatinib mesylate tablets versus IFN+Ara-C in patients with the newly diagnosed CML, 1.8% of patients had Grade 3/4 hemorrhage. In the Phase 3 unresectable or metastatic GIST studies, 211 patients (12.9%) reported Grade 3/4 hemorrhage at any site. In the Phase 2 unresectable or metastatic GIST study, 7 patients (5%) had a total of 8 CTC Grade 3/4 hemorrhages; gastrointestinal (GI) (3 patients), intra-tumoral (3 patients) or both (1 patient). Gastrointestinal tumor sites may have been the source of GI hemorrhages. In a randomized trial in patients with newly diagnosed Ph+ CML in chronic phase comparing imatinib mesylate tablets and nilotinib, GI hemorrhage occurred in 1.4% of patients in the imatinib mesylate tablets arm, and in 2.9% of patients in the nilotinib 300 mg twice daily arm. None of these events were Grade 3 or 4 in the imatinib mesylate tablets arm; 0.7% were Grade 3 or 4 in the nilotinib 300 mg twice daily arm. In addition, gastric antral vascular ectasia has been reported in postmarketing experience. 5.6 Gastrointestinal Disorders Imatinib mesylate tablets are sometimes associated with GI irritation. Imatinib mesylate tablets should be taken with food and a large glass of water to minimize this problem. There have been rare reports, including fatalities, of GI perforation. 5.7 Hypereosinophilic Cardiac Toxicity In patients with hypereosinophilic syndrome with occult infiltration of HES cells within the myocardium, cases of cardiogenic shock/left ventricular dysfunction have been associated with HES cell degranulation upon the initiation of imatinib mesylate tablets therapy. The condition was reported to be reversible with the administration of systemic steroids, circulatory support measures and temporarily withholding imatinib mesylate tablets. Myelodysplastic/myeloproliferative disease and systemic mastocytosis may be associated with high eosinophil levels. Consider performing an echocardiogram and determining serum troponin in patients with HES/CEL, and in patients with MDS/MPD or ASM associated with high eosinophil levels. If either is abnormal, consider prophylactic use of systemic steroids (1-2 mg/kg) for one to two weeks concomitantly with imatinib mesylate tablets at the initiation of therapy. 5.8 Dermatologic Toxicities Bullous dermatologic reactions, including erythema multiforme and Stevens-Johnson syndrome, have been reported with use of imatinib mesylate tablets. In some cases of bullous dermatologic reactions, including erythema multiforme and Stevens-Johnson syndrome reported during postmarketing surveillance, a recurrent dermatologic reaction was observed upon rechallenge. Several foreign postmarketing reports have described cases in which patients tolerated the reintroduction of imatinib mesylate tablets therapy after resolution or improvement of the bullous reaction. In these instances, imatinib mesylate tablets were resumed at a dose lower than that at which the reaction occurred and some patients also received concomitant treatment with corticosteroids or antihistamines. 5.9 Hypothyroidism Clinical cases of hypothyroidism have been reported in thyroidectomy patients undergoing levothyroxine replacement during treatment with imatinib mesylate tablets. Monitor TSH levels in such patients. 5.10 Embryo-Fetal Toxicity Imatinib mesylate tablets can cause fetal harm when administered to a pregnant woman. Imatinib mesylate was teratogenic in rats when administered during organogenesis at doses approximately equal to the maximum human dose of 800 mg/day based on body surface area (BSA). Significant post-implantation loss was seen in female rats administered imatinib mesylate at doses approximately one-half the maximum human dose of 800 mg/day based on BSA. Advise sexually active female patients of reproductive potential to use effective contraception (methods that result in less than 1% pregnancy rates) when using imatinib mesylate tablets and for 14 days after stopping imatinib mesylate tablets. If this drug is used during pregnancy or if the patient becomes pregnant while taking this drug, apprise the patient of the potential hazard to a fetus [see Use in Specific Populations (8.1)] . 5.11 Growth Retardation in Children and Adolescents Growth retardation has been reported in children and pre-adolescents receiving imatinib mesylate tablets. The long-term effects of prolonged treatment with imatinib mesylate tablets on growth in children are unknown. Therefore, monitor growth in children under imatinib mesylate tablets treatment [see Adverse Reactions (6.1)]. 5.12 Tumor Lysis Syndrome Cases of Tumor Lysis Syndrome (TLS), including fatal cases, have been reported in patients with CML, GIST, ALL, and eosinophilic leukemia receiving imatinib mesylate tablets. The patients at risk of TLS are those with tumors having a high proliferative rate or high tumor burden prior to treatment. Monitor these patients closely and take appropriate precautions. Due to possible occurrence of TLS, correct clinically significant dehydration and treat high uric acid levels prior to initiation of imatinib mesylate tablets. 5.13 Impairments Related to Driving and Using Machinery Motor vehicle accidents have been reported in patients receiving imatinib mesylate tablets. Advise patients that they may experience side effects, such as dizziness, blurred vision, or somnolence during treatment with imatinib mesylate tablets. Recommend caution when driving a car or operating machinery. 5.14 Renal Toxicity A decline in renal function may occur in patients receiving imatinib mesylate tablets. Median estimated glomerular filtration rate (eGFR) values in patients on imatinib mesylate tablets 400 mg daily for newly-diagnosed CML (four randomized trials) and malignant GIST (one single-arm trial) declined from a baseline value of 85 mL/min/1.73 m 2 (N = 1,190) to 75 mL/min/1.73 m 2 at 12 months (N = 1,082) and 69 mL/min/1.73 m 2 at 60 months (N = 549). Evaluate renal function prior to initiating imatinib mesylate tablets and monitor during therapy, with attention to risk factors for renal dysfunction, such as preexisting renal impairment, diabetes mellitus, hypertension, and congestive heart failure.