1. Fundamentals of Pharmacology for Veterinary Technicians
Chapter 9
Respiratory System Drugs
© 2004 by Thomson Delmar Learning, a part of the Thomson Corporation.

2. Basic Anatomy and Physiology
The respiratory system is the body system that brings oxygen from the air into the body for delivery via the blood to cells
Respiration is the exchange of gases between the atmosphere and the cells of the body
Ventilation is the bringing in of fresh air
© 2004 by Thomson Delmar Learning, a part of the Thomson Corporation.

3. Basic Anatomy and Physiology
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Respiratory Drugs
Expectorants
Increase the flow of respiratory secretions to allow material to be coughed up from the lungs
Increase the fluidity of mucus
An example is guaifenesin
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Respiratory Drugs
Mucolytics
Decrease the viscosity or thickness of respiratory secretions
An example is acetylcysteine (also used to treat acetaminophen toxicity)
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Respiratory Drugs
Antitussives
Suppress coughs
May be centrally acting or locally acting
Centrally acting antitussives include butorphanol, hydrocodone, codeine, dextromethorphan, and trimeprazine (in a combination product)
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Respiratory Drugs
Decongestants
Decrease the congestion of nasal passages by reducing swelling
Examples include phenylephrine and pseudoephedrine
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Respiratory Drugs
Bronchodilators
Widen the lumen of the bronchi and counteract bronchoconstriction
Examples include cholinergic blocking agents (anticholinergics such as aminopentamide, atropine, and glycopyrrolate), beta-2-adrenergic agonists (such as epinephrine, isoproteronol, terbutaline, and albuterol), and methylxanthines (such as aminophylline and theophylline)
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Respiratory Drugs
Antihistamines
Block the effects of histamine
Antihistamine drug names usually end with –amine
Side effects include CNS depression and anticholinergic effects such as dry mouth
Examples include diphenhydramine and chlorpheniramine
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Respiratory Drugs
Respiratory stimulants
Stimulate the animal to increase its respirations
Examples include naloxone (usually used to stimulate respiration following narcotic overdose) and yohimbine (used to reverse xylazine administration or overdose)
© 2004 by Thomson Delmar Learning, a part of the Thomson Corporation.