The developmental speed of new antimicrobials does not meet the emergence of multidrug-resistant bacteria sufficiently. A potential shortcut is assessing the antimicrobial activity of already approved drugs. Intrudingly, the antibacterial action of
glatiramer acetate (GA) has recently been discovered. GA is a well-known and safe immunomodulatory drug particular effective against Gram-negative bacteria, which disrupts biological membranes by resembling the activity of
antimicrobial peptides. Thus, GA can potentially be included in treatment strategies used to combat
infections caused by multidrug-resistant Gram-negatives. One potential application is chronic
respiratory infections caused by Pseudomonas aeruginosa, however the safety of GA inhalation has never been assessed. Here, the safety of inhaling nebulized GA is evaluated in a preclinical pig model. The potential side effects, i.e., bronchoconstriction, respiratory tract symptoms and systemic- and local
inflammation were assessed by
ventilator monitoring, clinical observation, biochemistry, flowcytometry, and histopathology. No signs of bronchoconstriction assessed by increased airway peak pressure, Ppeak, or decreased
oxygen pressure were observed. Also, there were no signs of local
inflammation in the final histopathology examination of the pulmonary tissue. As we did not observe any potential pulmonary side effects of inhaled GA, our preliminary results suggest that GA inhalation is safe and potentially can be a part of the treatment strategy targeting chronic lung
infections caused by multidrug-resistant Gram-negative bacteria.