Polymyxin-Associated Neurotoxicity: A Case of Guillain-Barré Syndrome Temporally Linked to Colistin Methanesulfonate and Respiratory Paralysis with Polymyxin B.

Polymyxins are critical for multidrug-resistant Gram-negative infections, yet severe neurotoxicity remains underrecognized, within Guillain-Barré Syndrome (GBS) has not been previously reported in association with polymyxin E. We report two cases illustrating a temporal association between polymyxin therapy and severe neurological manifestations. The first is a case of polymyxin B-induced respiratory paralysis in a patient with bloodstream infection. The second represents the first reported case of GBS associated with polymyxin E (Colistin Methanesulfonate) in a patient with pneumonia; the diagnosis was confirmed electrophysiologically, and the patient responded to immunotherapy. These findings suggest a potential link between polymyxin therapy and severe, atypical neurotoxicity. Clinicians should be vigilant for symptoms ranging from acute paresthesia to GBS, as early recognition and drug discontinuation are crucial to preventing severe outcomes.