Efficacy of salmeterol xinafoate in horses with recurrent airway obstruction.
OBJECTIVE
To determine the onset, magnitude, and duration of bronchodilation after administration of aerosolized salmeterol xinafoate in horses with recurrent airway obstruction.


METHODS
Randomized controlled study


METHODS
6 horses with recurrent airway obstruction. Procedure Horses received aerosolized salmeterol (210 microg) or no treatment, using a crossover design. Salmeterol was administered, using a mask designed for aerosol delivery in horses. Subjective rating of airway obstruction (RAO), maximal change in pleural pressure (deltaPplmax), and pulmonary resistance (RL) were determined at baseline; 5, 15, and 30 minutes; and 1, 2, 4, 6, 8, 10, and 12 hours after administration of salmeterol and in horses that did not receive treatment.


RESULTS
The deltaPpl and RL were improved 15 minutes through 6 hours after administration of salmeterol, compared with values obtained from horses receiving no treatment. The RAO was improved 15 minutes through 2 hours after administration of salmeterol. The maximal response to salmeterol was evident 30 to 60 minutes after administration and was characterized by a 59 + 19% decrease in deltaPpl and a 56 +/- 13% decrease in RL. The deltaPpl and RL were not different from baseline values 8 hours after salmeterol administration.


CONCLUSIONS
Duration of action of salmeterol in these horses was approximately 6 hours. Maximal bronchodilation was somewhat delayed (30 to 60 minutes), and the magnitude of response was similar to that of short-acting beta2-adrenergic agonists. Salmeterol provides moderately sustained bronchodilation in horses with recurrent airway obstruction and may be an effective drug for long-term control of this condition.
Henrikson
S L
SL
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan 66506-5606, USA.
Rush
B R
BR
D000280:Administration, Inhalation; D000402:Airway Obstruction / Q000188:drug therapy / Q000662:veterinary*; D000420:Albuterol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D001993:Bronchodilator Agents / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D018592:Cross-Over Studies; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D008168:Lung / Q000187:drug effects; D008297:Male; D012008:Recurrence; D000068299:Salmeterol Xinafoate; D016896:Treatment Outcome
D001993:Bronchodilator Agents; D000068299:Salmeterol Xinafoate; D000420:Albuterol