Lecture 59 – Respiratory Therapeutics

Question 1

Factors that influence asthma development

Answer 1

o Host factors
 Genetic
 Gender obesity
o Environmental factors
 Indoor allergens
 Outdoor allergens
 Chemical irritants
 Tobacco smoke
 Air pollution
 Respiratory infections

Question 2

Predominant characteristic of allergic (Th2-type) asthma

Answer 2

o Airway obstruction
o Increased airway hyperresponsiveness (AHR)
o Chronic eosinophilic airway inflammation

Question 3

Airway obstruction

Answer 3

o Mucous hypersecretion
o Occlusion of airway lumen
o Airway mucosal oedema
o Bronchial blood vessels leaky and dilated
o Swelling – encroachment on lumen

Question 4

FEV

Answer 4

o Forced expiratory volume

Question 5

Inflammation: cells and mediators

Answer 5

o Inflammatory cells e.g. mast cells
o Structural cells e.g. epithelial cells
o Mediators e.g. histamine
o Effects e.g. bronchospasm

Question 6

Key components of allergic (Th2 type) asthma pathogenesis

Answer 6

o Induction phase
o Smooth muscle shortening (bronchoconstriction
o Inflammation

Question 7

Strategies to target asthma

Answer 7

o Prevent development of allergy (difficult)
o Prevent or reverse the airway obstruction
o Prevent or reverse airway inflammation

Question 8

Drug delivery to the lungs

Answer 8

o From asthma pump
o 10-20% inhaled
o 80-90% swallowed

Question 9

Airway smooth muscles (ASM)

Answer 9

o Airway smooth muscle tone – balance of relaxation and constriction
o Bronchodilator response = relaxation of ASM
o Bronchoconstrictor response = contraction of ASM

Question 10

Short-acting Beta2 adrenoceptor agonists (SABA; reliever)

Answer 10

o Acute symptom relief of exercise-induced bronchoconstriction
o Must be used with inhaled corticosteroid
o Increased use needs to review – poorly controlled
o Frequent use associated with poor outcomes
o Rapid (2-5 mins) onset of action
o Duration 2-4 hours (diffusion not metabolism)
o E.g. salbutamol, terbutaline

Question 11

Long-acting beta2-adrenoceptor agonists (LABAs; preventer)

Answer 11

o Prophylaxis
o Reduce number of flare-ups
o Always combined with ICS in single actuator
o Benefit of chronic bronchodilatation
o E.g. salmeterol (slow onset, 12h duration), formoterol (rapid onset, 12h duration)

Question 12

Beta2-andrenoceptor agonist adverse effects and precautions

Answer 12

o Adverse effects = selectivity for the B2-adrenceptor is very important
o Precautions = cardiovascular disorders, diabetes (high doses), sympathomimetic amines

Question 13

Glucocorticoids (preventer)

Answer 13

o Main preventative treatment – regular daily treatment
o Decreases symptoms, flare-ups, risk of hospitalisation and death
o ICS = inhaled corticosteroid e.g. budesonide
o Systemic (oral, tablet or liquid) = serve asthma or acute flare-up e.g. prednisolone

Question 14

Adverse effects of inhaled glucocorticoids

Answer 14

o Well tolerated
o Hoarseness and weakness of voice
o Oral thrush
o Mouthwash reduced local absorption

Question 15

Systemic (oral) adverse effects of glucocorticoids

Answer 15

o Suppression of the hypothalamic-pituitary-adrenal axis
o Mood changes
o Weight gain
o Diabetes
o Osteoporosis