title: A pilot study comparing the antispasmodic effects of inhaled salmeterol, salbutamol and ipratropium bromide using different aerosol devices on muscarinic bronchoconstriction in healthy cats.
abstract: This study compared the duration and magnitude of the antispasmodic effects of salmeterol (SLM), salbutamol (SAL), ipratropium bromide (IB) and the combination of SAL and IB (SAL/IB) against carbachol-induced bronchoconstriction in healthy cats, and investigated the gain in efficacy using a two or fourfold increase in drug dosages. The drug regimens used were: (1) SLM 25 microg, SAL 100 microg, IB 20 microg and SAL/IB 100 microg/20 microg for bronchodilators delivered by a metered-dose inhaler (MDI); (2) SAL 3.75 mg and IB 62.5 microg for nebulised (NEB) medications. To monitor the bronchodilator effect, airway responsiveness was assessed at different time points using barometric whole-body plethysmography and calculation of the concentration of inhaled carbachol inducing a 300% increase of baseline Penh (enhanced pause), an estimator of airflow limitation. Maximum C-Penh300 was recorded 15 min after NEB SAL, IB MDI, NEB IB and 1h after SAL MDI and 4h after SLM MDI, respectively. C-Penh300 was significantly different from control values (without treatment) up to 24h for SLM MDI, 8h for IB MDI and 4h for other drugs. In terms of efficacy, SAL/IB MDI showed a synergistic antispasmodic effect at 15 min, 4h and 8h after administration. A fourfold increase of the initial dose of IB MDI and NEB IB significantly increased C-Penh300. Despite a fourfold dose increase, SLM displayed the weakest degree of bronchoprotection compared to other bronchodilators. The study provides evidence that inhaled bronchodilators are efficient at preventing muscarinic-induced bronchospasm in healthy cats and that SAL and IB appear to be short-acting bronchodilators in contrast to SLM.
authors.affiliation: Section of Pharmacology, Pharmacotherapy and Toxicology, Department for Functional Sciences B41, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Leemans
authors.forename: Nathalie
authors.initials: N
authors.lastname: Kirschvink
authors.forename: Frédérique
authors.initials: F
authors.lastname: Bernaerts
authors.forename: Cécile
authors.initials: C
authors.lastname: Clercx
authors.forename: Carole
authors.initials: C
authors.lastname: Cambier
authors.forename: Pascal
authors.initials: P
authors.lastname: Gustin
mesh_terms: D000280:Administration, Inhalation; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives; D000818:Animals; D016084:Bronchoconstriction / Q000187:drug effects*; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D002415:Cats / Q000502:physiology*; D005260:Female; D009241:Ipratropium / Q000008:administration & dosage; D008297:Male; D036501:Metered Dose Inhalers / Q000662:veterinary; D010865:Pilot Projects; D010993:Plethysmography, Whole Body / Q000662:veterinary; D000068299:Salmeterol Xinafoate
chemical_list: D001993:Bronchodilator Agents; D000068299:Salmeterol Xinafoate; D009241:Ipratropium; D000420:Albuterol