Background and Objectives: The aim of this study is to investigate the characteristics of gastrointestinal bleeding events associated with BCR-ABL tyrosine kinase inhibitor (TKI) treatment, using the reporting odds ratio (ROR) of the adverse event reports submitted to the Japanese Adverse Drug Event Report database between 2004 and 2020, and to examine the number of reported TKI-related gastrointestinal bleeding cases according to sex and age, as well as the actual number of TKI prescriptions issued in Japan. Materials and Methods: The RORs and 95% confidence intervals (CIs) of gastrointestinal bleeding events related to TKIs were calculated using the data of the 595,121 included cases. Results: Significant gastrointestinal bleeding events were detected for dasatinib (crude ROR: 4.47, 95% CI: 3.77–5.28) and imatinib (crude ROR: 1.22, 95% CI: 1.01–1.46). In multiple logistic regression analyses, significant gastrointestinal bleeding events were detected for dasatinib (adjusted ROR: 8.02, 95% CI: 5.75–10.2), imatinib (adjusted ROR: 1.81, 95% CI: 1.2–2.72), age (≥60 years, adjusted ROR: 2.22, 95% CI: 2.1–2.36), reporting year (adjusted ROR: 1.04, 95% CI: 1.04–1.05), and male sex (adjusted ROR: 1.47, 95% CI: 1.37–1.57). Interaction analysis revealed that the association of gastrointestinal bleeding with dasatinib was affected by age (≥60 years) and sex (female), with the number and proportion of dasatinib-related gastrointestinal bleeding cases increasing among those aged ≥60 years. Conclusions: Specific TKIs and patient characteristics were associated with gastrointestinal bleeding. Our results aid the prompt identification and treatment of TKI-related gastrointestinal bleeding.

Background and Objectives: Hyponatremia is among the most prevalent electrolyte abnormalities observed in patients with cancer during chemotherapy. Therefore, managing hyponatremia is crucial since it causes a severe electrolyte imbalance that can lead to significant mortality, and this study aimed to investigate the relationship between hyponatremia, anticancer drugs, and cancer types. Materials and Methods: Reported odds ratios were calculated and evaluated based on adverse event reports submitted to the Japanese Adverse Drug Event Report (JADER) database. Results: Overall, 2943 patients had hyponatremia. Notably, cisplatin, pemetrexed, and etoposide had marked hyponatremia signals. In addition, significant hyponatremia signals were detected for oesophageal, lung, and renal cancers. Conclusions: Hyponatremia has been reported in women and patients with lung cancer receiving cisplatin, with a growing trend in the number of elderly patients receiving cisplatin. Furthermore, since the onset of hyponatremia during cisplatin administration is frequently reported within 10 days, patient information should be thoroughly examined before and monitored throughout the administration, which can contribute to the early detection and prevention of hyponatremia.