Unit 8 - Respiratory Drugs Flashcards
What is doxapram?
A respiratory stimulant, emerg drug and brain stimulant
stims breathing if apnea or bradypnea
Reveres resp depression caused by CNS depressants (premeds, anesthetics)
Can use w/ opioi-induced resp depression if antagonists not available
S/e: due to non-specific brain stimulation = aggression, tremors, seizure, inc BP, arrhythmia)
give 1 drop under tongue of C-sec puppies
2nd choice to true reversal
Naloxone if opioid premed
yohimbine, antiseden if A2-premed
What does an antitussive mean? What is an example of it?
Used to treat non-productive (dry) coughs. Productive is normally indicated by a swallow afterwards
Ex. collapsing trachea; tracheitis from kennel cough, heart enlargement (heart pushes on trachea)
How do antitussives work?
stops by blocking cough reflex
1. centrally acting - act on cough center loc in the brain stem
2. local acting - sooth and coat the mucus lining where there is inflam/trauma/irritation so signals not sent to cough center
What are some locally acting antitussives OTC for dogs and horses?
buckley’s Zev OTC
may have some herbs that test pos a competitions so stop use 4 days before
What is dextromethorphan
(DM)
not controlled, easily found OTC
benylin - DM, robitussin - DM
often mixed w/ other drugs including acetaminophen, ibuprofen (must read labels)
How do opioids work as antitussives?
excellent cough suppresion. more effective than DM. controlled. can be addictive so risk of owner abuse
antitussive dose has no resp depression, minimal analgesia, possible constipation w/ chronic use, may see mild sedation
butorphanol, hydrocodone, codeine
what are expectorants and mucolytis?
for productive cough - increase fluid secretion in airways or reduce viscosity of airway mucus = mucus easier to remove. must keep patient hydrated, inhaled steam helps too
What role does guaifenesin play in respiratory drugs?
expectorant and mucolytic
expectorant in human OTC cough meds, mostly used for anes in vet patients
What role does sodium iodine play in resp drugs?
expectorant and mucolytic
cattle/horses given IV, not in preg or hyperthyroid patients
What role does dembrexine (sputolysin) play in resp drugs
mucolytic and some antitussive properties
oral powder for horses
What role does acetycysteine (mucomyst) play in resp drugs?
human product
oral, IV, nebulized
more commonly used to tx acetaminophen toxicity in cats
How do decongestants work?
A1 receptor agonist = vasoconstriction of vessels in MM = dec edema and secretions
BUT, most have some B1 activity therefore cause in HR as a side effect
commonly found in human cough/cold meds - Ex. pseudoephedrine, ephedrine, phenylephrine (poor oral bioavailability)
How do we treat asthma?
- remove any allergic triggers and dust
- anti-histamines; used more as prevention than treatment
- dilate airways - bronchodilators (very mild effect w/ anti-histamines
- Reduce inflammation - steroids - fluticasone, prednisolone, dexamethasone
What are anti-histamines and some commonly used drugs?
H1-blockers, blocks histamine from binding to receptors. they are better for longterm PREVENTIOn than tx; used in COPD, allergy, asthma
S/E: sedation; anticholinergic effects (dry mouth)
Pyrilamine - powder labeled for horses (with ephedrine)
Diphenyhydramine (benadryl) OTC human label, oral, injectable
What are some options of bronchodilators?
- beta-2 adrenergic agonists
- methylxanthines (aminophylline, theophylline) - CNS stimulation like caffeine
- Anticholinergic (atropine) - emergency/CPR bronchidilator
- Antihistamines - very mild bronchodilation; inhibits the histamine response that causes inflamm
