Asthma

Question 0

Pathophysiology

Answer 0

Symptoms of asthma result from a combination of inflammation and bronchoconstriction, so treatment must address both components

Question 1

Asthma

Answer 1

Chronic inflammatory disorder of the airway; characteristic signs and symptoms: sense of breathlessness, tightening of the chest, wheezing, dyspnea, cough
-Cause: immune mediated airway inflammation

Question 2

Two main pharmacologic classes

Answer 2

Anti-inflammatory agents: glucocorticoids (prednisone); bronchodilators: beta2 agonists (albuterol)

Question 3

Inhalation drug therapy

Answer 3

Three obvious advantages: therapeutic effects are enhanced, systemic effects are minimized, relief of acute attacks is rapid
-Three types: metered-dose inhalers (MDIs), dry-powder inhalers (DPIs), nebulizers

Question 4

Anti-inflammatory drugs

Answer 4

Foundation of asthma therapy, taken daily for long-term control, principal anti-inflammatory drugs are the glucocorticoids

Question 5

Glucocorticoids

Answer 5

Include budesonide and fluticasone, usually administered by inhalation, but IV and oral are also options; mechanism of action: suppress inflammation; adverse effects: minor when taken acutely, can be severe when used long-term (adrenal suppression, osteoporosis, hyperglycemia)

Question 6

Leukotriene Modifiers

Answer 6

Suppress effects of leukotrienes, less effective than inhaled glucocorticoids; available agents: zileuton (Zyflo), zarfirlukast (Accolate), montelukast (Singulair)

Question 7

Cromolyn

Answer 7

Used for prophylaxis, not for quick relief; supresses inflammation, not a bronchodilator
-Route: inhalation (nebulizer, MDI); adverse effects: safest of all antiasthma medications, cough, bronchospasm

Question 8

Bronchodilators

Answer 8

Provide symptomatic relief but do not alter the underlying disease process (inflammation); in almost all cases, patient taking a bronchodilator should be taking a glucocorticoid for long-term suppression of inflammation
-Principal bronchodilators are the beta2-adrengergic agonists

Question 9

Beta2-Adrenergic Agonists

Answer 9

Include albuterol, salmeterol, terbutaline; most effective drugs for relief of acute bronchospasm and prevention of exercise-induced bronchospasm
-Use in asthma: both quick relief and long-term control

Question 10

Beta2-Adrenergic Agonists: adverse effects

Answer 10

Inhaled preparations
-systemic effects: tachycardia, angina, and tremor
Oral preparations
-excessive dosage: angina pectoris, tachydysrhythmias; tremor

Question 11

Beta2-Adrenergic Agonists: Mechanism of action

Answer 11

Activate beta2 receptors in smooth muscle of lung, promoting bronchodilation and thereby relieving bronchospasm; also suppress histamine release in lung and increase ciliary motility

Question 12

Bronchodilators: methylxanthines

Answer 12

Theophylline: benefits derive primarily from bronchodilation, narrow therapeutic index, plasma level 10 to 20 mcg/mL, toxicity is related to theophylline levels
-other methylxanthines: aminophylline, dyphylline

Question 13

Glucocorticoid/LABA Combinations

Answer 13

Available combinations: fluticason/salmeterol (Advair), budesonide/formoterol (Symbicort); indicated for long term maintenance in adults and children, not recommended for initial therapy

Question 14

Tests of lung function

Answer 14

Forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF)

Question 15

Four classes of chronic asthma

Answer 15

Intermittent, mild persistent, moderate persistent, severe persistent

Question 16

Treatment goals of chronic asthma

Answer 16

Reducing impairment, reducing risk

Question 17

Long term drug therapy of Chronic Asthma

Answer 17

Agents for long term control (eg. inhaled glucocorticoids), agents for quick relief of ongoing attacks (eg. inhaled SABAs)

Question 18

Management of Chronic Asthma

Answer 18

Important to reduce exposure to allergens and triggers; sources of allergens: house dust mites, pets, cockroaches, mold
-Factors that can exacerbate asthma: tobacco smoke, wood smoke, household sprays

Question 19

Drugs for Acute Severe Exacerbations

Answer 19

Requires immediate attention, goal is to relieve airway obstruction and hypoxemia and normalize lung function as quickly as possible
Initial therapy:
1. Oxygen to relieve hypoxemia
2. Systemic glucocorticoid to reduce airway inflammation
3. Nebulized high-dose SABA to relieve airway obstruction
4. Nebulized ipratropium to further reduce airflow obstruction

Question 20

Reducing Exposure to Allergens and Triggers

Answer 20

Measures to control or avoid dust mites and their feces include: encasing pt’s pillows, mattress, box spring with covers impermeable to allergens, washing all bedding weekly in a hot water cycle, removing carpeting or rugs, keeping indoor humidity below 50%