Respiratory Drugs Flashcards
Respiratory Drugs
Commonly used to control the symptoms of respiratory tract disease by restoring normal function
Respiratory anatomy- Pathway
nasal cavity-> pharynx-> larynx-> trachea-> bronchi-> bronchioles-> alveoli
Functions of the respiratory tract
O2 and CO2 exchange
Body temperature regulation in dogs
Voice production
Maintenance of normal respiratory tract environment
must be highly humid and free of foreign debris
Nasal hair
filters out large particles
Nasal turbinates (concha)
trap small particles,
warm/humidify air
Mucociliary clearance
small particles are trapped in mucus, excreted by wavelike action of cilia
Coughing and sneezing
expel foreign debris forcefully
Laryngospasm and bronchoconstricion
prevent introduction of foreign debris into respiratory tract
Antitussive
Drugs that block the cough reflex
Centrally acting antitussives
suppress the cough center in the CNS
Butorphanol
Hydrocodone
Locally acting antitussives
prevent irritation of the the respiratory tract
Butorphanol (Torbutrol, Torbugesic)
- controlled drug
* causes little sedation at antitussive doses
Hydrocodone (Hycodan, Tussigon)
- controlled drug
- may cause sedation and constipation
- also provides analgesia
Mucolytics
Drugs that reduce the viscosity of mucus in the respiratory tract
*Viscosity of mucus may increase during infection or inflammation
Dextromethorphan
common ingredient in nonprescription cold and flu medications for humans
Codeine
found in many cough suppressants for humans
controlled drug
may produce sedation
Acetylcysteine (Mucomyst)
administered by nebulization
drug of choice to treat acetaminophen toxicity
Expectorants
- Drugs that increase the fluid consistency of mucus in the respiratory tract
- Act by stimulating parasympathetic nervous system receptors to increase respiratory fluid secretions
Oral medicationsInhaled vapors
Oral medications- Guaifenesin or saline solutions (ammonium chloride, sodium citrate, postassium iodide)
Inhaled vapors- volatile oils (terpin hydrate, eucalyptus oil, pine oil)
Bronchodilators
Drugs that relieve bronchoconstriction
Bonchoconstriction can be caused by:
parasympathetic nervous system stimulation
histamine release
prevention of sympathetic nervous system stimulation
Examples of Bronchodilators
- Beta-adrenergic agonists
- Methylxanthines
Beta-adrenergic agonists
- Beta-adrenergic agonists (terbutaline, clenbuterol, albuterol, metoproterenol)
- stimulate sympathetic nervous system receptors (β-2) involved in bronchodilation and stabilization of mast cells
- available in inhalant, oral, and injectable formulations
