Respiratory Pharmacology

Question 1

How can respiratory physiology be manipulated pharmacology?

Answer 1

Treatment of inflammation, pain, infection, neoplasia
Drugs to alter- bronchial diameter, antitussives, surfactants, mucolytics, expectorants, decongestants, affect respiratory centre

Question 2

How is bronchial diameter normally manipulated?

Answer 2

Bronchodilation (sympathetic), Bronchoconstriction (parasympathetic)
Autonomic nervous system- non-adrenergic, non-cholinergic nerves
Response to irritant receptors

Question 3

How can bronchial diameter be effected pharmacologically?

Answer 3

Autonomic agonists/antagonists

Drugs directly on smooth muscle

Question 4

What receptors stimulate sympathetic system of respiratory system and what does it cause?

Answer 4

B2 adrenoreceptors

Causes bronchi dilation, increased action of mucocilliary escalator, recedes release of inflammatory mediators

Question 5

What stimulates the parasympathetic portion of the respiratory system and what does it cause?

Answer 5

Muscarinic receptors

Causes bronchoconstriction and increased mucus production

Question 6

What are the effects of alpha/beta sympathetic stimulation in other parts of the body?

Answer 6

Alpha:
Vasoconstriction 
Intestinal sphincter contraction 
Intestinal sphincter contraction 
Pupil dilation 

Beta: 
Vasodilation
increased HR
Bronchodilation
Bladder relaxation 
Metabolic stimulation

Question 7

What respiratory drugs act directly on smooth muscle and what is their mechanism of action?

Answer 7

Methylxanthines

MOA- phosphodiesterase inhibitors, adenosine antagonists- increasing cAMP- affects myosin light chain kinase- relaxation

Question 8

What are the side effects of methylxanthines?

Answer 8

Taccycardia, excitability, seizures, derangement of GI motility

Question 9

When should anti-tussives be used?

Answer 9

If a cough is non-productive, or when patient becomes exhausted

Question 10

What is the mode of action and the direct and indirect effect of antitussives ?

Answer 10

MOA- Opioids suppress the ill defined cough centre of the brain
Direct effect- suppress cough centre in medulla oblongata, reduction of stimulus to cough

Question 11

What are examples of opioids used as antitussives and what are the side effects?

Answer 11

Codeine and butorphanol

Side effects- sedation, suppression of CNS, constipation

Question 12

What are surfactants and what is their use?

Answer 12

Lipid molecules generated from bovine lung extract- administered for neonate distress syndrome in premature births

Question 13

What are the effects of mucolytics?

Answer 13

Decrease viscosity of bronchial secretions- improves clearance- more easily moved and coughed

Question 14

What are two examples of mucolytics, their modes of action, administration and side effects?

Answer 14

Bromhexine HCL
MOA- enhances hydrolysis of mucopolysaccharides, ineffective in presence of infection or inflammation doe to presence of protein
Oral or parenteral administration

N-acetylcyteine
MOA- breaks disulphide bonds between mucus molecules, effective in infection/inflammation
Topical administration
Side effects- bronchoconstriction and airway irritation

Question 15

What do expectorants do and how and name two examples?

Answer 15

Thought to irritate the gastric mucosa, increasing vagal tone and therefore increase bronchial secretion

Potassium Iodide
Guaifenesin

Question 16

What are decongestants used for?

Answer 16

Used to recuse nasal mucosa thickness to enable easier passage of air

Question 17

What are examples of decongestants?

Answer 17

Ephedrine, pseudoephedrine, phenylephrine

Poorly tolerated in animals

Question 18

What is an example of a respiratory stimulant, what is its effects?

Answer 18

Doxapram
Increases chemoreceptor sensitivity, RR and tidal volume
Topical or parenteral

Question 19

What is the preferred method of administration for respiratory diseases?

Answer 19

Aerosol administration

Question 20

What are 4 adrenoreceptor agonists?

Answer 20

Adrenaline
Noradrenaline
Ephedrine
Isoproterenol

Question 21

What is the best adrenoreceptor agonists for bronchodilation?

Answer 21

Beta 2 agonists

Question 22

What are some examples of a beta 2 agonists, how are they administered?

Answer 22

Terbutaline- highly selective at normal dose
Parenteral, topical or oral uptake
Albuterol- selective- oral or topical administration rapid by topical
Clenbuterol- selective, orally administered

Question 23

What are the adverse effects of beta 2 agonists?

Answer 23

BP abnormalities
Tacycardias
Hypokalaemia
Seizures

Question 24

What effect will adrenoreceptor antagonists have on the respiratory system?

Answer 24

Bronchocontstriction

Question 25

What would a drug need to effect to cause bronchial dilation?

Answer 25

Parasympathetic antagonists

Question 26

What type of parasympathetic antagonists is used in the respiratory system for bronchodilation?

Answer 26

Anticholinergics

Question 27

What are the systemic effects of anticholinergics?

Answer 27

``` Tacycardia Dry mucous membranes Reduced GI motility Mydriasis Hypertension ```

Question 28

What is an example of anticholinergic used for bronchodilation and how is it administered?

Answer 28

Ipatropium- topical