Lecture 13 - Respiratory Pharmacology Flashcards
What phases does asthma have?
Early and late phases
What is asthma characterised by?
Airway Inflammation
Bronchial hyper-reactivity
Reversible airway obstruction
When is asthma observed as reversible?
Once allergens that are responsible for reaction has been removed
What can degree of obstruction be monitored by?
Spirometry (lung function)
What is FEV1?
Forced expiratory volume in 1 second
What is FVC?
Forced vital capacity
What is the equation for spirometry?
FEV1/FVC
What is PEFR?
Peak expiratory flow rate
What is bronchospasm?
Smooth muscle constriction
When does late phase occur?
After immediate phase because of certain mediators that are generated and released during the immediate phase
Immediate phase of asthmatic attack
Occurs abruptly
Caused by spasm of bronchial smooth muscle
Allergen interaction with mast cell-fixed IgE cause release of histamine, leukotriene B4 and prostaglandin
What are other mediators of immediate phase?
IL-4 IL-5 IL-13 Macrophage inflammatory protein-1alpha Tumour necrosis factor TNA-alpha
When the allergens are inhaled what does it cause?
Mast cell degranulation
How do you relieve smooth muscle constriction?
Beta-2 adrenoceptor agonist
What does inflammatory cell include?
Activated eosinophils
What does activated eosinophils release?
Cysteinyl leukotrienes Interleukin IL-3 IL-5 IL-8 Toxic proteins (eosinophil cationic protein) Major basic protein Eosinophil derived neurotoxin
What can late phase be inhibited by?
Glucocorticoids
What is Glucocorticoid and what does it do?
Steroid hormone
Interrupt the link between T helper cells and accumulation of eosinophils
What is the long term effect of changes occurring in the bronchioles?
Hypertrophied smooth muscle
What is hypertrophied smooth muscle?
Changes in the smooth muscles which make it more reactive/liable to reduce the diameter of the bronchioles
What is an example of changes to be lining of bronchioles?
Thickened basement membrane
What formation is seen during asthma attack?
Formation of mucus plug with eosinophils and desquamated epithelial cells
Further restrict the flow of air through the bronchioles
What are the main drugs used for bronchodilators?
B2-adrenoceptor agonist
Theophylline
What are examples of bronchodilators?
Cysteinyl leukotriene receptor antagonist
Muscarinic receptor antagonist