10 - Drugs & Asthma/COPD Flashcards
(74 cards)
1
Q
What is COPD?
A
- Slowly progressive airway obstruction due to chronic inflammation
- Includes chronic bronchitis (inflammation of bronchi) and emphysema (destruction of alveolar structures)
2
Q
What are clinical sx of COPD?
A
- Cough
- Mucous hypersecretion
- Dyspnea (SOB)
3
Q
What is asthma?
A
- Chronic inflammatory disorder of airways
- Recurring episodes of hyper-responsiveness to stimuli that causes bronchoconstriction
- Based on triggering stimuli characterized as extrinsic (allergenic) or intrinsic (non-allergenic)
4
Q
What are the clinical sx of asthma?
A
Recurring episodes of cough, wheezing, tight chest, and dyspnea
5
Q
What occurs in extrinsic asthma?
A
- External stimuli (dust, mold, pollen, animal dander) trigger plasma cells to produce antigen specific IgE antibodies
- Allergen and IgE bind to mast cells => degranulation and release of inflammatory mediators
- Allergens usually have some glycoproteins that immune cells recognize as an antigen
6
Q
What are some non-allergenic factors that can trigger asthma?
A
Anxiety, stress, cold air, dry air, smoke, exercise
7
Q
What is the mechanism of intrinsic asthma?
A
- Not completely understood
- Abnormalities in autonomic regulation of airway functions
- Involvement of innate immune system
- ACh is released during stress, and stimulates muscarinic receptors which control smooth muscle of bronchi
8
Q
What are the acute and prolonged responses of asthma?
A
- Acute = bronchoconstriction (w/in minutes)
- Prolonged = vasodilation, mucous secretion, edema, and bronchoconstriction (occurs hours later)
9
Q
Which symptoms of asthma and COPD can be helped w/ drug therapy?
A
- Excessive airway smooth muscle tone
- Inflammation
- Mucous plugging
- Pulmonary edema
- Non-productive cough
10
Q
Which drugs are bronchodilators?
A
- Beta-adrenergic agonists
- Methylxanthines
- Anticholinergics
- Leukotriene modifiers
11
Q
Which drugs are anti-inflammatory agents?
A
- Corticosteroids
- Mast cell stabilizers
- Anti-IgE monoclonal antibody
- Leukotriene modifiers
12
Q
What are bronchodilators?
A
Agents that interact w/ smooth muscle cells lining the airways and relax smooth muscles
13
Q
Examples of beta-adrenergic agonists used for asthma and COPD
A
- Albuterol/salbutamol
- Terbutaline
- Salmeterol
14
Q
Example of methylxanthine used for asthma and COPD
A
Theophylline
15
Q
Examples of anticholinergics used for asthma and COPD
A
- Tiotropium
- Ipratropium
16
Q
Examples of leukotriene modifiers used for asthma and COPD
A
- Zileuton
- Zafirlukast
- Montelukast
17
Q
What is the symp NS effect on bronchiole smooth muscle?
A
Beta 2 receptor causes bronchodilation
18
Q
What is the para NS effect on bronchiole smooth muscle?
A
Muscarinic receptor (M3) causes bronchoconstriction and increased secretions
19
Q
Describe how the para NS causes bronchoconstriction
A
ACh binds to M3 receptors => activation of Gq => PLC activation => increased DAG and IP3 hydrolysis => increased cytoplasmic Ca2+ => Ca2+-calmodulin activates myosin, which binds to actin => contraction
20
Q
What effect does adenosine have on Ca2+ levels?
A
Adenosine increases Ca2+ levels
21
Q
Describe how the symp NS causes bronchodilation
A
Activation of beta 2 receptor => activation of Gs => adenylyl cyclase activation => ATP converted into cAMP => PKA activation => decrease in cytoplasmic Ca2+ and prevents myosin binding to actin => dilation/relaxation
22
Q
What is the MOA of beta agonists for asthma?
A
Stimulate adenylyl cyclase => increased formation of cAMP which relaxes airway smooth muscle
23
Q
How are beta agonists administered for asthma?
A
Typically via inhalation (terbutaline can be administered subcutaneously and in tablet form and albuterol can be administered in tablet)
24
Q
Which beta agonists are long acting and which are short acting?
A
- Short acting = albuterol and terbutaline
- Long acting = salmeterol
25
What is the drug of choice for acute asthma attacks?
Albuterol inhaler
26
What is the drug of choice for severe asthma attacks?
Subcutaneous injection of terbutaline or epinephrine may be required along w/ corticosteroids
27
Why are beta agonists recommended to be administered w/ corticosteroids for asthma?
Prevent development of desensitization and promote efficacy of beta agonists
28
What are adverse effects of beta agonists?
- Beta 1 receptors on heart may get stimulated, causing tachycardia
- Skeletal muscle tremor
- Tolerance
29
What are drug interactions w/ beta agonists?
Propranolol for HTN or other heart conditions
30
What is the MOA of methylxanthines?
- Inhibits phosphodiesterase => increased cAMP which relaxes airways
- Inhibits adenosine receptors
- Can stimulate contractility of diaphragmatic muscles
31
What is the safest route of administration for theophylline?
Aerosol
32
What is theophylline indicated for?
- Second choice for acute asthmatic attacks
- COPD
- May reverse steroid insensitivity
33
What are some adverse effects of theophylline?
- Common = headache, insomnia, tremors
| - Serious = anaphylactic shock, N/V, fever, seizures
34
What is a caution w/ theophylline?
Increased CV effects if given w/ beta 2 agonists
35
Which anticholinergics are short acting and which are long acting?
- Short = ipratropium
| - Long = tiotropium
36
What is the MOA of anticholinergics?
- Blocks muscarinic receptors, preventing bronchial constriction and mucous secretion
- No effect on inflammation
37
How are anticholinergics administered?
Aerosol
38
What is the indication for ipratropium?
- Tx of COPD and chronic bronchitis
- Tx of acute asthma attacks in children, adults and those intolerant to beta agonists
- Enhances bronchodilation produced by beta agonists
39
What are adverse effects of ipratropium?
- Aerosol is generally well tolerated, but excessive use may cause atropine like effects (dry mouth, dilated pupils, tachycardia)
- Caution w/ glaucoma and prostatic hypertrophy
40
What effect do leukotrienes have in the lungs?
Cause bronchoconstriction, increased bronchial reactivity, mucosal edema, and secretion of mucous
41
What are leukotriene modifiers?
Drugs that inhibit synthesis of leukotrienes or block the receptors that leukotrienes act upon
42
What is the MOA of zileuton?
Inhibits 5-lipoxygenase, which is the enzyme that catalyzes formation of leukotrienes from arachadonic acid
43
What is the route of administration of zileuton?
Oral, administered 4 times per day
44
What is the indication of zileuton?
- Tx of persistent asthma in adults and ASA-induced asthma
| - Prevents exercise and antigen-induced bronchospasm
45
What is an adverse effect of zileuton?
Possible hepatotoxicity
46
What is the MOA of zafirlukast and montelukast?
Selective reversible inhibitors of CysLT1 receptor, preventing leukotriene induced bronchoconstriction and airway wall edema
47
What is the route of administration for zafirlukast?
Oral, administered twice daily
48
What is the indication for zafirlukast?
- Tx of mild to moderate asthma (only for px 8 y/o and older)
- Less effective than corticosteroids
49
What are some adverse effects of zafirlukast?
- Headache, GI disturbance
| - Inhibits CYP450, which may interfere w/ metabolism of other drugs
50
What is the route of administration for montelukast?
Oral, administered once daily
51
What is the indication of montelukast?
- Modestly effective in tx of persistent asthma in children over 6 y/o and adults
- Less effective than corticosteroids
52
What do anti-inflammatory agents do?
- Reduce inflammation, edema, and mucous production
| - Counteract airway inflammation, reducing asthma attacks and COPD flares/progression
53
What are examples of corticosteroids for asthma and COPD? How is each administered?
- Beclometasone
- Flunisolide
- Fluticasone
- Budesonide
- Mometasone (first 5 are inhaled)
- Methylprednisolone (IV)
- Prednisone (oral)
54
What are examples of mast cell stabilizers?
Cromolyn sodium and nedocromil
55
What is an example of an anti-IgE monoclonal antibody?
Omalizumab
56
What is the difference between glucocorticoids and mineralocorticoids?
- Glucocorticoids regulate glucose metabolism
| - Mineralocorticoids regulate salt and water balance
57
What is the MOA of corticosteroids for asthma and COPD?
- Block release of arachidonic acid
- Increase sensitivity of beta receptors and prevents their desensitization
- Prevent long term changes in airway structure and function
58
What is the route of administration of corticosteroids for asthma?
- Aerosol is preferred to limit systemic side effects
| - Severe exacerbations may require IV (methylprednisolone) or oral (prednisone)
59
What are indications of corticosteroids?
- Aerosol used in moderate cases of asthma and COPD
| - First line of anti-inflammatory therapy
60
What are some adverse effects of corticosteroids?
- Aerosol can cause oropharyngeal candidiasis and hoarseness
- Chronic use may suppress adrenal glands
- Common and permanent = osteoporosis and cataracts in adults; growth retardation in children
- Common and reversible = edema, weight gain, delayed wound healing
61
How can adverse effects of corticosteroids be reduced?
Alternate day therapy for oral medication and morning administration
62
What are the indications for mast cell blockers?
- Cromolyn sodium = tx of mild to moderate asthma of all ages
- Nedocromil = tx of mild to moderate asthma in px 12 y/o and older
- Anti-inflammatory drug of choice for tx of allergenic asthma in children (over 2 y/o)
- Prevention of exercise induced asthma
63
What is the MOA of mast cell blockers?
- Poorly understood
- Inhibit release of mediators from mast cells, possibly by blocking ion channels required for degranulation
- Helps w/ intrinsic and extrinsic asthma
64
What is the route of administration for mast cell blockers?
Aerosol, administered 2-4 times per day
65
Should mast cell blockers be used in acute asthmatic attacks?
Doesn't reverse ongoing bronchoconstriction, but regular use reduces bronchial hyper-reactivity and inhibits acute and chronic responses
66
How long should mast cell blockers be trialed?
4-6 weeks
67
What are some adverse effects of mast cell blockers?
- Throat irritation, dryness, cough, nasal secretion, congestion
- Anaphylaxis, hives, low BP, tightness in chest
68
What is the MOA of omalizumab?
- Selectively binds human free IgE, preventing IgE binding to cells and reduces IgE levels
- Reduces both acute and prolonged inflammatory responses
69
What is the indication of omalizumab?
Allergic asthma
70
What is the route of administration of omalizumab?
Subcutaneous injection
71
What are the goals of therapy for asthma and COPD?
- Maintain normal activity levels
- Maintain near normal pulmonary function rates
- Prevent troublesome sx (cough, breathlessness at night or during exertion)
- Avoid adverse effects of medications
- Avoid drug interactions
72
What are the characterizations for severity of asthma?
- Mild intermittent = less than 2 bronchoconstrictive episodes per week, peak expiratory flow (PEF) normal
- Mild persistent = more than 2 episodes per week; PEF above 80%
- Moderate persistent = 6 episodes per week or daily episodes; PEF over 60%
- Severe = continual; PEF less than 60%
73
What is the recommended COPD tx by severity?
- Mild = bronchodilators
- Moderate = bronchodilators and anti-inflammatories
- Severe = antibiotics, bronchodilators, and anti-inflammatory drugs w/ oxygen therapy
74
What is the recommended asthma tx by severity?
- Every px w/ asthma should use environmental control and should have a short acting beta 2 agonist on demand
- As severity goes from mild to severe, dosing of inhaled corticosteroid should increase
