Abstract
Piperacillin/tazobactam is a widely used anti-infective agent. However, prolonged use can lead to adverse drug reactions, primarily presenting as fever and various abnormal laboratory test results. Certain abnormal test outcomes may mislead clinical assessments. We present a case of a 50-year-old Chinese woman who developed a fever and abnormal blood tests after receiving piperacillin/tazobactam for more than 2 weeks. These tests showed elevated levels of C-reactive protein, procalcitonin, transaminases, myocardial enzymes, and a significant increase in D-dimer. After stopping piperacillin/tazobactam, all relevant test results returned to normal within 10 days. It is imperative for clinicians to be vigilant of this adverse effect in patients undergoing extended piperacillin/tazobactam treatment, as early recognition can prevent unnecessary diagnostic tests and therapeutic interventions.