Potential drug interactions between targeted oral antineoplastic agents and concomitant medication in clinical practice.

OBJECTIVES: Our objective was to analyze potential drug interactions (PDIs) between targeted OAAs and concomitant therapy in clinical practice. METHODS: A cross-sectional observational study was performed in cancer outpatients who started treatment with a targeted OAA between 1 December 2015 and 31 May 2019. PDIs were analyzed using the Lexicomp® and the database About Herbs®. PDIs were classified according to severity, risk, and reliability ratings and their underlying mechanism. Univariate and multivariate analysis were performed to identify risk factors associated with PDIs. RESULTS: A total of 881 patients were included, of whom 50.9% had at least 1 PDI between the OAA and the concomitant medication. The factors associated with a higher risk of PDIs were polypharmacy (≥5 concomitant medicines) (OR = 3.64 (2.54-5.20), p < 0.001), type of tumor (prostate cancer [OR = not available, p < 0.001], chronic myelogenous leukemia [OR = 5.10 (1.08-24.05), p = 0.040], sarcoma [OR = 4.97 (1.05-23.55), p = 0.043]), and treatment with hormone therapies (OR = not available, p < 0.001). CONCLUSION: A search of PDIs should be prioritized, especially in patients receiving targeted OAAs with risk factors, such as polymedication, prostate cancer, chronic myelogenous leukemia, sarcoma, and treatment with hormone therapies.