ch 9 Respiratory drugs pharm I

the respiratory tract begins where

at the nose

what is the rhinarium

the nosepad

acupuncture point on the philtrum just under the nostrils that can be used to stimulate respiration


this structure warms, moistens, filters air, and increases the surface area of the nasal cavity

nasal turbinates

areas in the skull that insulate delicate structures, lighten the skull, and moisten and warm air


respiratory area above the hard and soft palate


mouth area below the hard and soft palate


the caudal area of the throat is called

pharynx (throat)

the opening of the trachea is called

larynx (voice box)

structure made of series of c-shaped cartilage rings that have annular ligaments between each ring for support


the trachea branches into bronchi at the

hilus or carina (bifurcation process)

cells that secrete mucus in the upper respiratory tract

goblet cells

the upper respiratory tract is lined with cilia and mucus that function to

trap foreign particles and move them out of the respiratory tract

structure lined with smooth muscle that can be dilated with sympathetic nervous stimulation or constricted with parasympathetic nervous stimulation


small, sac like structures where oxygen and carbon dioxide diffuse
produce lipoprotein, surfactant


lipoprotein produced by alveoli
keeps the alveoli open by reducing surface tension of small sacs, absence of lipoprotein would cause alveoli collapse


the lower respiratory tracts begins after which structure


body system that brings oxygen from the air into the body for delivery via blood to cells

respiratory system

the exchange of gases (oxygen and carbon dioxide) between the atmosphere and cells of the body


term used to describe the bringing in or fresh air


bronchi end in alveoli where capillaries exchange CO2 for O2
this structure is the site of oxygen exchange



lung collapse

inflammation and possible infection of the bronchi


inflammation of lungs caused by bacterial invasion of the tissues or by aspirating of foreign substances into lower respiratory tract
cranial ventral most common


slowly progressive disease of the airways characterized by gradual loss of lung function
in horses is commonly called heaves

COPD chronic obstructive pulmonary disease

respiratory drugs used to treat upper respiratory conditions include

expectorants, mucolytics, antitussives, and decongestants

expectorant: increases flow of mucus production so it can be coughed out
common in OTC
side effects: mild, increase HR, decreases BP, can be harmful if used on dogs with heart disease
also used in horses as a muscle relaxant, as part of general anesthesia

Guaifenesin (Guailaxin, Gecolate, Robitussin Cough Syrup, Triaminic)

drugs that increases fluidity of respiratory secretions (mucus) to allow material to be coughed up from the lungs
also helps to keep dry, irritated tissue moist
ex. Guaifenesin


drugs that thins the viscosity (thickness) of respiratory secretions by breaking them down
ex. acteylcysteine


mucolytic: breaks up thick mucoid secretions in airway to promote better respiration
also reverses methemoglobinemia caused by acetaminophen toxicity
can be given IV, oral, or nebulized (fine mist)

Acetylcysteine (Mucomyst, Mucosol)

drugs that suppress
central acting- act on cough centers of brain stem
locally acting- soothing irritation to the mucosal lining that initiates cough (syrups or lozenges not commonly used in vet med)
NOT USED with infectious Dz becaus


centrally acting antitussive: suppresses cough
non addictive
also used for pain control & as preanesthetic sedative
side effects: sedation, ataxia, respiratory depression
injection or oral tablet

Butorphanol (Torbugesic, Torbutrol)

centrally acting antitussive: suppresses cough
commonly used on harsh nonproductive coughs
side effects: sedation and constipation
tablet or syrup forms

Hydrocodone (Hycodan, Tussigon)

centrally acting antitussive: suppresses cough
C-II to C-IV depending on formulation (may be mixed with other aspirin, acetaminophen, or guaifenesin
side effects: sedation and constipation
injectable, syrup, and tablet forms


centrally acting antitussive: suppresses cough
non addictive
non narcotic but chemically similar to codeine in action
safe for dogs
avoid other ingredients often in combination
not very effective in nonhumans
cough syrups


centrally acting antitussive: suppresses cough
non narcotic
combination antitussive & prednisolone (glucocorticoid)
has antipruritic (itching) effects
phenothiazine derivative
used for allergic rhinitis and bronchitis
side effects: sedation, PU/PD, hypote

Trimeprazine (Temaril-P)

drugs that decrease congestion by swelling in nasal passages
may be given as a spray, topically, orally
Adrenergic (sympathetic, epinephrine & norepinepherine, produced & secreted by adrenal medulla)
ex. Phenylephrine, Pseudoephedrine


decongestant: reduces swelling of nasal cavity
has cardio-stimulatory properties, should not be used in animals with hypertension or tachycardia
side effects: hyperexcitability, hypertension, tachycardia
oral or topical

Phenylephrine ( Neo-Synephrine)
Pseudoephedrine (Sudafed)

drugs that widen the lumen of the bronchioles and counteract bronchoconstriction
decreases resistance and increases air flow
parasympathetic stimulation causes release of acetylcholine(neurotransmitter) which binds to B2 receptors (in lungs) causing bronc


cholinergic blockers or anticholinergics
bind to receptor sites of acetylcholine and block cholinergic agents to prevent bronchoconstriction
side effects: dry mouth, dry eyes, tachycardia
not commonly used due to side effects
also used fo

Aminopentamide (Centrine), Atropine, Glycoyrrolate (Robinul)

B 2 adrenergic agonists
stabilize mast cells and decrease histamine release
side effects: tachycardia, CNS excitement
nebulized, injectable, or oral

Epinephrine, Terbutaline, Albuterol,
Clenbuterol(illegal use in food animals)

works by inhibiting enzyme in smooth muscle cells that cause bronchoconstriction
when inhibited, bronchodilation occurs
side effects: CNS stimulation and GI irritation

Aminophylline, Theophylline,
Theobromine (common in coffee & chocolate)

list a few effects of the sympathetic autonomic system

bronchodilation, decreases peristalsis, dry mouth, hypertension, tachycardia

name a few effects of the parasympathetic autonomic system

bronchoconstriction, hypersalivation, increased secretions, hypotension, increased peristalsis

which are the neurotransmitters for the sympathetic nervous system

epinephrine and norepinephrine

what is the neurotransmitter for the parasympathetic nervous system


drugs that block the effects of histamines (chemical relaeased by mast cells) combining with H1 receptors on bronchiole smooth muscle that cause bronchoconstriction
histamine has systemic effects
commonly used to prevent heaves in horses,

Dipenhydramine (Benadryl), Chlorpheniramine (ChloroTrimeton), Hydroxyzine, Clemastine

drugs that stimulate the animal to increase its respirations
ex. Doxapram, Naloxone, Yohimbine

respiratory stimulants

respiratory stimulant:
central acting
used for increasing respiration during anesthesia or recovery in neonates after C-section
(can stimulate manually by rubbing and pinching bodies)
can also use GV26 acupuncture point if you do not have drug
side effect


respiratory stimulant:
specific use for reversal of narcotic overdose (narcotic antagonist)
short acting, may need to be given repeatedly until P is stable


respiratory stimulant:
used to reverse Xylazine (Rompun) sedation
side effects: CNS stimulation and tremors
can be given IV or IM
in people used as weight loss supplement and aphrodisiac