Asthma Drugs Flashcards
How do Beta 2 adrenergic receptor agonists work?
By directly acting on B2 adrenoreceptors on bronchiole smooth muscle to relax the muscle
Also inhibit mediator release from mast cells and monocytes
May act on cilia to increase mucus clearance
What are the different types of bronchodilator?
Beta 2 adrenergic receptor agonists
Theophylline
Muscarinic receptor antagonists
Leukotrine receptor antagonists
How are B2 agonists administered?
By inhalation
Which drugs are B2 adrenergic receptor agonists?
Salbutamol
Terbutaline
Salmeterol
What are the side effects associated with B2 agonists and how are they caused?
Most common is tremor
Result from absorption into systemic circulation
When is theophylline used?
As a second line drug with a steroid when asthma response to B2 agonist is inadequate
Given IV in acute severe asthma
What are the side effects associated with theophylline?
Tremor
Sleep disturbance
Vasodilation
Anorexia
Nausea
Vomiting
When are muscarinic receptor antagonists used, and which is the main drug used if this type?
Used adjunct to B2 agonists and steroid when these are insufficient to control asthma
Main drug used is ipratropium
Given by aerosol inhalation
What are the actions of muscarinic antagonists, and what is the mechanism for these actions?
Relax bronchial smooth muscle
Inhibit elevated mucus secretion in asthma
May increase clearance of bronchial secretions
Caused by blocking the action of endogenous acetylcholine at muscarinic receptors
When are leukotriene receptor antagonists used?
To prevent exercise-induced and aspirin sensitive asthma
Main use as an add on for uncontrolled, mild-moderate asthma
Give two examples of leukotriene receptor antagonists
Montelucast
Zafirlukast
How do leukotriene antagonists work?
Act at cysteinyl-leukotriene receptors on bronchiole smooth muscle cells
Prevent actions of LTC4 and LTD4, preventing bronchial spasm and mucus secretion
Which group of drugs are used as anti-inflammatory drugs in the treatment of asthma?
Name three of the drugs in this group
Glucocorticoids:
Budesonide
Beclometasone diproprionate
Fluticasone propionate
Prednisolone
Hydrocortisone
How do glucocorticoids work in the treatment of asthma?
By reducing the production of cytokines, spasmogens (LTC4 AND LTD4) and leukocyte chemotaxins (LTB4 and PAF)
Therefore reducing bronchospasm and the recruitment and activation of inflammatory cells
How does theophylline work?
By blocking cyclic nucleotide phosphodiesterase, resulting in an accumulation of cAMP, which reduces intracellular calcium and causes smooth muscle relaxation
