Polymyxin use associated with respiratory arrest.

The polymyxins (polymyxin B and E) are bactericidal polypeptide antibiotics first discovered in 1947 and used for the treatment of gram-negative bacterial infections. Renal and neurologic toxicities coupled with the increasing availability of effective alternatives led to declining use in the 1960s. The emergence of multidrug-resistant organisms in the past decade has resulted in a resurgence in the use of polymyxins in critically ill patients, yet the side effects are not well known. We report two cases of respiratory arrest likely due to polymyxin B infusions in the context of a 10-fold increase in the use of polymyxin B in our institution over the past 10 years.