Pulmonary pharmacology

Question 1

What are potential targets of pulmonary therapeutics

Answer 1

Airway inflammation
Narrowed airways, increased smooth muscle
Constriction
Increased resistance

Bronchoconstriction

Irritation & cough

Infection

Question 2

Describe sympathetic stimulation of bronchodilation

Answer 2

Β2 adrenoreceptors

Noradrenaline acting as agonist

Relax smooth muscle in lung

Dilation via increased cAMP

Question 3

Describe parasympathetic stimulation of bronchoconstriction

Answer 3

Muscarinic receptors

M3 receptors:
Decrease cellular cAMP
Increased mucus secretion
Contraction of bronchial smooth muscle

M1 receptors:
Increased mucus secretion

Question 4

Describe what pulmonary therapeutics do

Answer 4

Modify airway resistance by manipulating bronchial tone

B2 agonists & M3 antagonists used to reduce airway resistance
B2 agonists: epinephrine, isoprenaline, salbutamol or clenbuterol
M3 antagonists: atropine, tiotropium or ipratropium

Question 5

What pulmonary drugs are used to decrease inflammation

Answer 5

Antihistamines
H1 antagonists

Glucocorticoids (steroids)
Reduce mucosal oedema
Reduce release of inflammatory mediators
Sensitise membranes to beta agonists
Prolong half life of adrenaline

Question 6

Describe role of respiratory stimulants, mucolytics & cough suppressants

Answer 6

Respiratory stimulants
Doxapram hydrochloride
Stimulate peripheral chemoreceptors & CNS
Used in CPR

Mucolytics
e.g. expectorants: oils, turpentine
Stimulate glandular cells
Breakdown mucus –> decrease viscosity
Increases expulsion

Cough suppressants
e.g. antitussives: opioids/opiates
Non-productive coughs
Mechanical irritation
Inhibit medullary oblongata cough centre