Respiratory drugs Flashcards
Doxapram is and used for
Resp stimulants
Emergency drug
Brain stimulant
Stimulates breathing if apnea (stopped) or bradypnea (very slow)
Reverses respiratory depression caused by CNS depressants (e.g., premeds and anesthetics)
Can use with opioid-induced respiratory depression if antagonists not available*
1 drop under tongue of C-Sec. puppies
Side effects of Doxapram
S/e: due to non-specific brain stimulation (aggression, tremors, seizure; also ↑BP, arrhythmia)
When to use doxapram and how
1 drop under tongue of C-Sec. puppies
Doxapram is 2nd choice to true reversal
Naloxone if opioid pre-med
Yohimbine, Antisedan if alpha-2 premed
Antitussives are and when to use
Used to treat non-productive (dry) coughs
E.g. Collapsing trachea; tracheitis from kennel cough, heart enlargement (heart pushes on trachea)
Stops cough by blocking the cough reflex
How do antitussives work
Centrally acting – act on the cough center located in the brainstem
Local acting – soothe and coat the mucus lining where there is inflammation/trauma/irritation so signals not sent to cough center
Locally acting antitussives are and ex
Not as common in veterinary patients.
Buckley’s Zev OTC for horses and dogs.
-May have some herbs that test positive at competition.
-Label advised stop use 4 days prior to competition.
Centrally active antitussives are
Stop cough by blocking the cough center in the brainstem
Examples of centrally acting antitussives
Dextromethorphan (DM)
Opiods
Dextromethorphan (DM) as an centrally active antitussive
Not controlled. Easily found OTC
Benylin®-DM, Robitussin®-DM
Often mixed with other drugs incl. acetaminophen, ibuprofen (must read labels)
Opioids as a centrally acting antitussives
Excellent cough suppression. More effective then DM. Controlled. Can be addictive; risk of owner abuse
Antitussive dose has no respiratory depression, minimal analgesia, possible constipation with chronic use, may see mild sedation
Butorphanol (“Torb”), Hydrocodone (Hycodan®), Codeine
Expectorants and mucolytics are and used for
For productive cough - Increase fluid secretion in airways or reduce viscosity of airway mucus= mucus easier to remove
Keep patient hydrated, inhaled steam helps too
Guaifenesin is and used for
Expectorants and mucolytics
expectorant in human OTC cough meds.
Mostly used for anesthesia in veterinary patients.
Sodium iodide is and used for
Expectorants and mucolytics
Cattle and horses given IV
Not in pregnant or hyperthyroid patients
Dembrexine (Sputolysin) is and used for
Expectorants and mucolytics
oral powder for horses
Mucolytic and some antitussive properties
Acetylcysteine (Mucomyst®) is and how to use
Expectorants and mucolytics
Human product
Oral, IV, nebulized
More commonly used to treat acetaminophen toxicity in cats.
Decongestants work for what receptors
α1 receptor agonists = vasoconstriction of vessels in mucus membranes =↓edema and secreons
BUT, most have some β1 receptor activity therefore cause ↑HR as a side effect.
Commonly found in human cough/cold medications
How to treat asthma
Remove any allergic triggers and dust
Anti-histamines; used more as a prevention than treatment
Dilate airways - bronchodilators
Very mild effect with anti-histamines
Reduce inflammation
Steroids- fluticasone (Flovent®), prednisolone, dexamethasone
Anti-histamines (H1-blockers) are
Diphenyhydramine (Benadryl®) OTC human label, oral and injectable
Pyrilamine– powder labelled for horses (with ephedrine)
Histamine released by mast cells triggers acute inflammation & bronchoconstriction
Drugs block histamine binding to receptors
Better for long-term prevention than treatment; used in COPD, allergy, asthma
Antihistamine side effects
Side effects: sedation; anticholinergic effects (e.g., dry mouth)
Options for type of bronchodilators
Widen the bronchi to increase airflow
Many options:
Beta-2 adrenergic agonists
-Most commonly used
Methylxanthines – ex. aminophylline, theophylline
-CNS stimulation. Think “caffeine”
Anticholinergics (atropine)
-Emergency/CPR bronchodilator
Antihistamines
-Very mild bronchodilation; inhibits the histamine response that causes the inflammation
Beta-2 adrenergic agonists as bronchodilators are
Airway irritation leads to bronchoconstriction
Βeta 2-adrenergic agonists bind to and activate the beta-2 receptors in the lungs causing bronchodilation & stabilize mast cells = less histamine release.
Salbutamol (Ventolin®), terbutaline, albuterol is what type of drug and used how
Beta 2 adrenergic agonists
Given with an MDI dispenser (puffer) in small animals
Local administration decreased dose and systemic side- effects
Indications of beta 2 adrenergic agonsits
Indications: collapsing trachea, asthma
Side-effects: stimulation of β1-receptors in the heart = ↑HR
Beta 2 adrenergic agonists for equine asthma are
Clenbuterol (Ventipulmin®) – oral syrup/injectable – equine
Caution at end of pregnancy – reduces uterine contractions.
