The Possible Relationship Between Adverse Drug Reactions and Potential Drug–Drug Interactions in Patients with NSCLC Treated with EGFR Inhibitors

Background: The introduction of targeted therapy in oncology has led to several challenges. These medicines are relatively new in clinical practice and are not well known to specialists with regard to adverse drug reactions (ADRs) and potential drug–drug interactions (pDDIs). In addition, cancer affects multiple body systems, including weight loss, anemia, liver and kidney function, depression, and pain. Patients frequently have comorbidities, leading to polypharmacy and the use of special foods, nutritional supplements, and herbal products for self-medication. Identification of pDDIs is essential, as concomitant use of multiple medicinal products increases the risk of ADRs and may compromise treatment. Objective: This study aims to retrospectively review and analyze data on ADRs and pDDIs in the treatment of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) inhibitors and to evaluate the relationship between them. Method: EudraVigilance and UpToDate® Lexidrug™ application were used to screen suspected ADRs and pDDIs, respectively. Descriptive statistical analysis was performed. Results: After reviewing Line Listing Reports (LLRs) from 2021 to 2023 in EudraVigilance, the number of suspected adverse drug reactions (ADRs) reported was higher when drug interactions classified as risk categories D and X were identified, compared with cases involving EGFR inhibitor monotherapy or other drug combinations. Of the 144 cases involving category D and/or X interactions, 63 demonstrated a possible association with the reported ADRs of EGFR inhibitors. The most common pDDIs detected were erlotinib–ranitidine (14 cases, category D) and osimertinib–amiodarone (13 cases, category D). Conclusions: Although EGFR inhibitors improve overall and progression-free survival in NSCLC, screening for pDDIs before treatment is essential to improve safety and quality of life.