ABSTRACT
INTRODUCTION: Cancer patients are particularly at risk for drug interactions. However, in oncology, this risk has not been studied in depth in France. The main objective of this study was to describe the proportion of drug interactions in patients with lung or digestive cancer. METHODS: The drug prescriptions of 93 patients were analyzed from may 27th, 2019 to July 07th, 2019 using two software programs (Thériaque™ and DDI Predictor™) in oncology patients hospitalized in our comprehensive cancer center. RESULTS: Of the 88 patients included in the study, 544 drug interactions were identified, in 66 patients (75.0%, 95% CI: 64.6-83.6). For 20/88 patients (22.7% CI: 14.5-32.9) a non-recommended combination or a theoretical contraindication was reported. Etoposide was the anticancer molecule most involved in combinations that are contraindicated or not recommended. No combinations defined as not recommended or contraindicated were observed in any of the 49 patients treated with chemotherapy during their hospitalization. The most common toxicities were alertness and metabolic disorders, including hyperkalemia. The use of three or more drugs was a risk factor for drug interactions (83 vs. 23%, P<0.001). CONCLUSION: Drug interactions remain a major concern in cancer hospitalized patients. It is important to continue and strengthen the collaboration between physicians and pharmacists in order to better prevent their occurrence.