Airway Effects of Inhaled Quaternary Ammonium Compounds in Mice

Abstract Quaternary ammonium compounds ( QAC ) constitute a family of widely used chemical substances. The QAC benzalkonium chloride ( BAC ) has caused bronchoconstriction in human beings by poorly understood mechanisms and lung damage at high concentration as shown in a single rat study. This study evaluates acute airway effects in mice after inhalation of aerosols of the QAC s, BAC , hexadecyl trimethyl ammonium bromide ( HTA ), cetyl pyridinium chloride ( CPC ) and dimethyl dioctadecyl ammonium bromide ( DDA ). The QAC s gave rise to concentration‐dependent decreases in the tidal volume ( VT ) and a concomitant increase in respiratory rate indicating pulmonary irritation. The potencies of the QAC to induce these effects were in the order: BAC > HTA = CPC > DDA . Furthermore, inhalation of BAC and CPC aerosols gave rise to pulmonary inflammation as apparent from bronchoalveolar lavage. Stimulation of nasal trigeminal nerve endings by QAC , which may serve as a warning signal, was absent.