Pharmacology of Asthma Flashcards
What are the different triggers for asthma?
Infection
Allergy
Exercise
NSAID asthma
What is allergy induced asthma also known as?
Atopic asthma
What might cause allergy induced asthma?
Smoke
Dust mites
What are the two stages of an asthma attack?
Early: Brochospasm
Late: Inflammation
What is SABA?
Short acting beta agonist
What is an example of a SABA?
Salbutamol
What is the mechanism of action for SABA?
Targets the Beta 2 adrenergic receptor on bronchiole smooth muscle cells
Acts as an agonist
Reduces Ca2+ entry and prevents smooth muscle contraction
What does activation of the M2 muscarinic receptors?
Bronchoconstriction
What is the LAMA?
Long acting muscarinic antagonist
What is a nebuliser?
Delivers the drug directly and locally
What is a spacer?
Makes inhalers easier to use and delivers the drug more effectively
What is the difference between oral or inhaled delivery?
Inhalation delivers drug directly and locally
Goes straight to the site of action, less likelihood of being broken down via enzymes in the liver
Faster action
Orally goes via the mouth into the stomach and undergoes first past metabolism
Why is a nebuliser used in an emergency situation?
Do not need coordination
Delivers mist automatically
What are the advantages of a nebuliser?
Many drug solutions
Can deliver combinations
Minimal patient cooperation required
Can deliver to patient of all ages
What percentage of SABA is able to influence lung function?
20% penetrates deep enough into the lungs to be able to influence lung function
What happens to the other 80% of inhaled salbutamol?
Oesophagus Goes into oral cavity Absorbed by mucus membrane Exhalation Muco-cillary clearance Absorbed by Lung
Why is spacer useful?
Reduces extent of loss via exhalation
Lower percentage of drug that is delivered immediately so less is breathed out
What is the mechanism of action of fluticasone?
Acts on the Glucocorticoid receptor located on immune cells specifically eosinophils in asthma
Reduces action of IL-5
Reduces the number of immune cells and therefore inflammatory response
What is the mechanism of action of Montelukast?
Leukotriene receptor antagonist
Blocks the leukotriene receptors reducing bronchorestrictive effects
Decreased bronchoconstriction
What is NSAID induced asthma?
NSAIDs block cyclo-oxygenases
Increses arachidonic acid
Increases leukotrienes
Bronchoconstiction via over activation of leukotrienes
