Download RESPIRATORY DRUGS 1. ANTITUSSIVES

RESPIRATORY DRUGS
1. ANTITUSSIVES
-Drugs that block the cough reflex. Cough reflex occurs when receptors in the airway send impulses to the
brainstem which causes contraction of the muscles needed to cough. The type of cough produced depends on
the location of the stimulated receptors and whether or not mucus is brought up with the cough (productive
or non productive).
-Antitussives given to animals are centrally acting. They suppress the neurons located in the brainstem’s cough
center.
-Antitussives should be used with caution since coughing is a protective mechanism. Animals with very
productive coughs or coughs with very sticky mucus should be allowed to occur as the body may be relying on
the cough to prevent the airway from being obstructed by mucus.
-Antitussives are often used with tracheitis, tracheobronchitis. When coughing worsens the inflammation that
is already present and stimulates more coughing, it needs to be suppressed.
A. BUTORPHANOL (Torbutrol, Torbugesic)
-Opioid cough suppressant in Class IV that is also commonly used for pain control.
-Won’t cause as much respiratory or cardiovascular suppression as hydrocodone or codeine and also
causes less sedation.
B. HYDROCODONE (Hycodan)
-Opioid cough suppressant in Class III
-Strong antitussive, however sedation is often noted as well as constipation if used long-term
-Can also mask pain
C. CODEINE
-Range from Class II to Class V, depending on if it is combined with any other drugs. Codeine alone is in
Class II.
-Sedation, nausea, and constipation may be seen
D. DEXTROMETHORPHAN
-Not a controlled substance, no pain control.
-Most commonly used cough suppressant in people, found in OTC cough, flu, and cold medications.
Often combined with other medications. Make sure it does not contain Tylenol if giving to cats!
-Not as effective as the other types of antitussives
2. MUCOLYTICS, EXPECTORANTS, DECONGESTANTS
A. MUCOLYTICS (ACETYLCYSTEINE-MUCOMYST)
-If mucus is thick or sticky, the cilia may be unable to move it toward the mouth to be coughed up.
-These agents break up mucus and reduce its viscosity, making it easier to move.
-Break up disulfide bonds in mucus that attributes to its viscosity.
-Med has an unpleasant taste so tablets are either flavored or the product is nebulized
B. EXPECTORANTS (Guafenesin, Ammonium chloride, Potassium iodide, Sodium citrate)
-Liquefy mucus, reducing its adhesiveness
-Indicated when a productive cough is present.
-Also cause irritation of the gastric mucosa and stimulation of the parasympathetic nervous system.
-Vomiting can be a side effect.
-Ideally should not be used with an antitussive, but the antitussive will not be able to completely
suppress the cough caused by the increased secretions.
C. DECONGESTANTS (PSEUDOEPHEDRINE, EPHEDRINE, PHENYLEPHRINE)
-Reduce vascular engorgement of swollen nasal tissues
-Stimulate alpha one receptors to vasoconstrict vessels leading to skin and mucous membranes. When
the engorged vessels are constricted, edema and mucous secretions are reduced.
-Stimulation of Beta one receptors is a side effect so increased heart rate may be seen. Use with
caution in patients with cardiovascular disease.