title: Endotracheal nebulization of N-acetylcysteine increases airway resistance in cats with experimental asthma.
abstract: N-acetylcysteine (NAC), a mucolytic and antioxidant, is speculated to cause bronchoconstriction in cats when delivered via aerosol. We hypothesized that in cats with experimental asthma, aerosol delivery of NAC (400mg cumulative dose) via an endotracheal tube would increase airflow limitation as measured by ventilator-acquired mechanics. After endotracheal drug delivery, airway resistance and inspiratory plateau pressure (Pplat) measurements were obtained in six mechanically ventilated asthmatic cats. Results demonstrated significantly increased airway resistance (P=0.0007) compared with aerosolized saline control; Pplats were not significantly different (P=0.059). All cats exhibited at least one adverse effect: excessive airway secretions (n=3), spontaneous cough (n=2), unilateral strabismus (n=1) and post-anesthetic death (n=1). No adverse reactions were noted with saline aerosol; cough was noted in one cat with methacholine challenge. In conclusion, airway resistance and adverse reactions were documented in all cats after NAC aerosol delivery. Further studies must be performed to evaluate if it is an effective mucolytic and/or antioxidant in cats and to determine if bronchodilator pre-treatment will negate NAC-induced bronchoconstriction.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, 900 East Campus Drive, Columbia, MO 65211, USA. reineroc@missouri.edu
authors.forename: Carol R
authors.initials: CR
authors.lastname: Reinero
authors.forename: Tekla M
authors.initials: TM
authors.lastname: Lee-Fowler
authors.forename: John R
authors.initials: JR
authors.lastname: Dodam
authors.forename: Leah A
authors.initials: LA
authors.lastname: Cohn
authors.forename: Amy E
authors.initials: AE
authors.lastname: DeClue
authors.forename: Vamsi P
authors.initials: VP
authors.lastname: Guntur
mesh_terms: D000111:Acetylcysteine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D000336:Aerosols; D000403:Airway Resistance / Q000187:drug effects*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001249:Asthma / Q000188:drug therapy / Q000662:veterinary*; D016084:Bronchoconstriction / Q000187:drug effects; D002415:Cats; D004195:Disease Models, Animal; D016503:Drug Delivery Systems / Q000379:methods / Q000662:veterinary*; D005100:Expectorants / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D005260:Female; D007442:Intubation, Intratracheal / Q000662:veterinary; D008297:Male; D016896:Treatment Outcome
chemical_list: D000336:Aerosols; D000975:Antioxidants; D005100:Expectorants; D000111:Acetylcysteine