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20 Cards in this Set
- Front
- Back
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What are the 4 main classes of drug used in the anti-inflammatory treatment of asthma/copd?
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Corticosteroids
Cromolyns LT pathway modifying agents Anti-IgE antibodies |
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What is the action of cromolyns?
What is the mechanism by which they accomplish this action? |
They prevent the allergic response to an antigen by preventing the activity and degranulation of mast cells with no effect on IgE binding. Not specific to mast cells however. Can improve cough.
They interrupt Chloride ion transport and Ca influx. |
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What are cromolyns primarily used for?
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Prophylaxis for specific triggers
Exercise induced asthma (taken before) Seasonal allergic asthma (prophylaxis) |
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What are the limitations of these agents?
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They are less effective in moderate to severe asthma.
Weak anti-inflammatory effects Short duration of action. No bronchodilator effects (not used for acute attacks) |
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What are the main adverse effects?
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Nasal and Throat Irritation
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What are the 4 main classes of drug used in the anti-inflammatory treatment of asthma/copd?
|
Corticosteroids
Cromolyns LT pathway modifying agents Anti-IgE antibodies |
|
|
What is the action of cromolyns?
What is the mechanism by which they accomplish this action? |
They prevent the allergic response to an antigen by preventing the activity and degranulation of mast cells with no effect on IgE binding. Not specific to mast cells however. Can improve cough.
They interrupt Chloride ion transport and Ca influx. |
|
|
What are cromolyns primarily used for?
|
Prophylaxis for specific triggers
Exercise induced asthma (taken before) Seasonal allergic asthma (prophylaxis) |
|
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What are the limitations of these agents?
|
They are less effective in moderate to severe asthma.
Weak anti-inflammatory effects Short duration of action. No bronchodilator effects (not used for acute attacks) |
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What are the main adverse effects?
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Nasal and Throat Irritation
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What are the main LT modifying agents? What are their mechanisms of action?
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Zileuton - LOX inhibitor
Montelukast - LT receptor antagonist Zefirlukast - LT receptor antagonist |
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What are the target cells of this therapy and the effect on those cells?
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Smooth muscle cells
Endothelial cells Leukocytes Goblet cells Increased cAMP, decreased Ca causing bronchodilation. |
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There are 3 therapeutic strategies using LT modifying agents. The first is inhibiting LOX (zileuton) reducing the synthesis of LTA4. The second is the inhibition of the cys-LT1 receptor, which is stimulated by LTC4, LTD4 and LTE4 (Montelukast)
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The third mechanism is inhibition of FLAP, the protein that activates LOX. These agents are not yet approved.
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What is the action of LTB? Cys-LT?
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Cell infiltration and activation
SM contraction, vasopermeability |
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LT modifying agents inhibit contraction (bronchodilation), inhibit microvascular leakage, mucus production and eosinophil/basophil influx into the airways.
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Only 30% of patients have a leukotriene driven asthma. Therefore, these agents only work on 30% of the asthma population.
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What is Montelukast indicated for?
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Prophylaxis and treatment of chronic moderate or severe asthmatics. It has few symptoms and less frequent use than inhaled beta agonists.
Not indicated for rapid bronchodilation. Use saba's for rescue. May be used to prevent exercise induced asthma. These agents are less efficacious than GCs and Beta 2 agonists, but offer an alternative if symptoms of the other two are not worth the benefits. |
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Describe the pros and cons of the LTMA oral tablet.
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Better compliance
Can be used to treat other co-existing allergic diseases (allergic rhinitis) but has higher systemic adverse effects than the inhaled formulation. |
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Describe the limitations of LTMA's.
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They are less effective than GCs
They do not block LTB4 (important in severe asthma) Limited effects on lung function and symptom control |
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In what patients would you want to use LTMA's with caution?
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Patients that are hepatically impaired because of the rare hepatotoxicity of Zileuton
Pregnant/Lactating patients. LTMA's are rarely associated with Churg-Strauss syndrome |
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What combination of the aforementioned agents is used as primary therapy?
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Salmeterol + Fluticasone
LABA + ICS |
