Adverse Events of Imatinib

Tunisia Introduction: Imatinib is a tyrosine kinase inhibitor used in cancer treatment mainly indicated in chronic myeloid leukemia (CML) and gastrointestinal stromal tumors [1]. Despite its effectiveness, it exposes to frequent adverse events (AE). Objective: Study clinical and epidemiological characteristics of imatinib AEs notified to the Tunisian National Centre of Pharmacovigilance. Methods: Retrospective study of AEs attributed to imatinib, notified to the National Centre of Pharmacovigilance between January 2010 and December 2018. Imputability was studied using the method of Begaud et al. [2]. Plasma concentration was determined by high performance liquid phase chromatography. Results: This study included 32 patients. The age ranged from 13 to 88 years old (median = 59 years). The F/M sex ratio was 1.28. Imatinib was indicated for the treatment of CML in 17 patients, GIST in 14 patients and desmoid tumor in one patient. Daily dose was 400 mg/day in 71.9% of cases. Plasma concentration was measured in seven patients. It was infratherapeutic in 3 cases (including one case of neutropenia) and superior to 1000 ng/ml in 4 cases. The most common AEs were: skin damage (47.4%), edema (21%), gastrointestinal damage (15.8%) of which 30% were nausea and vomiting, haematological damage (15.8%) such as neutropenia (50%) and thrombocytopenia (33.3%). The onset delay varied from few days to 3 years. Outcome was favorable in 77.5% of cases. The responsibility of imatinib was assessed as I1 (40.6%) and I2. Conclusion: This work highlights the characteristics of imatinib AEs. Cutaneous damage are the most common AE. Adverse events are usually of toxic mechanism and can be controlled either by a reduction of the dose or by a temporary interruption of the treatment [3].