Polymyxin B Induced Acute Diaphragmatic Paralysis: A Case Report Based on Therapeutic Drug Monitoring.

Polymyxin B (PMB), a last-resort antibiotic for multidrug-resistant Gram-negative infections, carries significant neurotoxicity risks that remain underrecognized in clinical practice. Here, we present a case of life-threatening diaphragmatic paralysis induced by PMB in a patient with extensive neck and mediastinal infections caused by extensively drug-resistant Acinetobacter baumannii. The patient developed acute respiratory failure due to respiratory paralysis, which resolved completely upon PMB discontinuation. Concurrent use of nephrotoxic agents may have contributed to renal impairment during treatment. This case is helpful in detecting the serious neurotoxic reactions caused by PMB at an early stage; systematic therapeutic drug monitoring combined with real-time renal function assessment aided in the early detection of toxicity, thereby preventing a potentially fatal outcome.