Risk Factors of Afatinib Induced Diarrhea: A Retrospective Study

Abstract

Afatinib is an irreversible oral ErbB family blocker. It demonstrates a side-effect profile similar to that by the first-generation epidermal growth factor receptor-tyrosine kinase inhibitor, with diarrhea being the most frequently reported adverse event (AE). Moderate and severe diarrhea can have a significant effect on patients' quality of life (QOL).

In this study, we retrospectively investigated the medical records of 66 afatinib-treated patients between May 2014 and December 2015, aiming to identify the risk factors for associated diarrhea.

Multivariate logistic regression analysis showed that being female (odds ratio = 5.370, 95% CI = 1.050-27.50, P = 0.044) and abnormal stool hardness (loose or hard) (odds ratio = 4.820, 95% CI = 1.170-19.90, P = 0.030) were significant risks for moderate to severe diarrhea associated with afatinib. Thus, we identified the risk factors for afatinib-associated diarrhea at the start of afatinib administration. This provides useful knowledge on managing the side effect and helps maintain patients' QOL. Furthermore, we showed the necessity of checking the condition of patients' stool prior to afatinib administration.