Respiratory pharm and therapeutics

Question 1

name 3 diseases which require bronchodilators and the species they affect

Answer 1

RAO - horses
asthma - cats
chronic bronchitis - dogs

Question 2

name a short acting B adrenergic agonist

Answer 2

adrenaline

Question 3

name 3 longer acting B adrenergic agonists

Answer 3

terbutaline, salbutamol, clenbuterol

Question 4

what is the mechanisms of action of bronchodilators?

Answer 4

bronchial sm innervated by B2 receptors. cause increase in cAMP so relaxation of sm therefore bronchodilation

Question 5

what is the problem with using adrenaline and how is it administered?

Answer 5

non-specific so acts on heart and bv’s. used for anaphylaxis as unsuitable for longterm used

IV/ IM

Question 6

what formulations is adrenaline in? and how do you calculate mg/ml?

Answer 6

1:1000 (0.1%) and 1:10000 (0.01%)

to get mg/ml x % by 10

Question 7

what is the benefit of using salbutamol, clenbuterol or terbutaline?

Answer 7

the are specific so only affect bronchial sm (B2) and not heart. longer acting so can be used long term.
available for inhalation

Question 8

describe the properties of terbutaline

Answer 8

often used in cats with asthma. oral/ inject in emergency

lasts 6-8h

Question 9

describe the properties of salbutamol

Answer 9

= ventolin. used in inhalers

Question 10

describe the properties of clenbuterol

Answer 10

= partial agonist so less effective. licensed for use in horses

Question 11

what are adverse effects of B agonists

Answer 11

stim symp system - tachycardia, vasoconstriction (B1 mainly), tremors, and tolerance so use in phases

Question 12

what is cromolyn used for?

Answer 12

stabilises mast cells so inhibits release of histamine leading to reduced bronchoconstriction. Must be given before allergen exposure - used in horses with RAO

Question 13

Give an example of a methylxanthine and explain its properties

Answer 13

theophylline. relaxes sm and poss anti-inflammatory. licensed in dogs, given as extended release capsules (dose less frequently) orally, highly bioavailable. commonly used for CB and asthma (SE in horses)
SE conc dependent - V, cardiac (symp), CNS poss seizures.
SE = V, cardiac, CNS

Question 14

what are anticholinergic drugs used for?

Answer 14

muscarinic (parasymp) antagonists. used in horses but not dogs and cats.

Question 15

give 3 examples of anti-cholinergics and describre SE

Answer 15

hyoscine - mainly used for colic but also emergency bronchodilator IV
atropine - emergency IV, ileus, tachycardia and CNS toxicity
ipratroprium - aerosol, less SE

Question 16

describe the cough reflex

Answer 16

irritation in bronchi/ trachea, sensory nerves, medulla oblongata, cough

Question 17

What are B agonists antitussive?

Answer 17

because they cause bronchodilation

Question 18

what drug type are often used for antitussives?

Answer 18

opioids

Question 19

name and explain the properties of an opioid used as an antitussive

Answer 19

butorphanol. kappa agonist. oral/ inject. poor oral bioavailability so need higher doses.

(also others - codeine, morphine = mu agonists)

Question 20

give and example of a non-opiate used as an antitussive

Answer 20

dextromethorphan. may or may not be effective but available over the counter. be aware of other toxic medicines e.g. paracetamol

Question 21

why might eucalyptus oil be used?

Answer 21

expectorant - increases tract secretions

Question 22

what is guaifenesin used for?

Answer 22

anaesthesia, muscle relaxant + increase secretions

Question 23

Give an example of a mucolytic drug and explain its properties

Answer 23

bromhexine - stimulates increase in secretion of fluids, breaks down mucoid sputum, increases mucociliary clearance.
may increase antibiotic availability in pigs and cattle
available as injection (PCo) and powder (PCoCD)

Question 24

what is acetylcysteine used for?

Answer 24

mucolytic - rarely used in vet med

antidote for paracetamol poisoning in cats

Question 25

what is nebulisation?

Answer 25

creation of small droplets of a drug that can be delivered to the airways. less systemic absorption so useful for drugs e.g. glucocorticoids

e.g. salbutamol

Question 26

how would you treat a horse with RAO?

Answer 26

management changes, bronchodilators, corticosteroids (laminitis), mucolytics

Question 27

how would you treat dogs with CB?

Answer 27

management, bronchodilators (oral/ inhaled), glucocorticoids, antibiotics if infections, not really muco/ antitussive as contra-indicated

Question 28

how would you treat cats with asthma

Answer 28

rule out other causes (smoking, scented candles, air fresheners), management, glucocorticoids (oral/ inhaled), bronchodilators

Question 29

name a glucocorticoid used in an inhaled form

Answer 29

fluticasone