Atrial fibrillation during palliative chemotherapy with utidelone: a case report.

This report describes a 57-year-old male patient with metastatic breast cancer who experienced atrial fibrillation during the infusion of utidelone as palliative chemotherapy. All cardiological examinations conducted before treatment were normal. There was no evidence of thyroid dysfunction, nor any objective data indicating acute or chronic cardiovascular disease. Other combination drugs have been used in clinical practice for decades and rarely have proarrhythmic activity. The innovative drug utidelone, independently developed in China, was approved by the National Medical Products Administration (NMPA) of China in 2021 for the treatment of patients with metastatic breast cancer. Cardiotoxicity has not been prominently reported in prior clinical trials of utidelone. Although a definite causal relationship cannot be confirmed, the close temporal association and clinical course suggest that utidelone may have contributed to the arrhythmias. This case highlights the need for careful cardiac monitoring during treatment.