resp tract drugs: asthma and COPD

Question 1

SNS action

Answer 1

NE or Epi bind to alpha or beta adrenoreceptors (fight or flight)
- a1: blood vessels contract
- b1: increase HR and FOC
- b2: bronchi smooth muscle relax (Epi)

Question 2

PNS action

Answer 2

Ach bind to nicotinic (skeletal muscle) or muscarinic cholinergic receptors (rest and digest)
- m: contract muscle cell of bronchi and slow HR

Question 3

bronchial asthma

Answer 3

recurrent and reversible SOB
- tiggers: dist, viral infection, cold, smoke, exercise, pollutants
- occurs when lung airways narrow
- bronchospasms: contraction of bronchi smooth muscle
- inflammation of bronchial mucosa (edema and increased secretions)

happens bc mast cells activated by triggers release chemicals: histamine, leukotrienes, prostaglandins
- chemicals can directly cause bronchospasms and can attract immune cells = inflammation

Question 4

asthma symptoms/signs

Answer 4

• narrowed airway (limited airflow)
• edema
• inflammation
• thickened airway wall
• mucus
• tightened bronchiole smooth muscle
• alveolar ducts open but airflow obstructed
• difficulty breathing
• wheezing

Question 5

status asthmaticus

Answer 5

medical emergency
- prolonged asthma attack, not responding to medical therapy

Question 6

COPD

Answer 6

1) chronic bronchitis: bronchial edema/hypersecretions
2) emphysema (alveolar destruction- barrel chest, SA for gas exchange reduced
- progressive condition
- can have exacerbations
- main cause smoking

Question 7

types of respiratory tract drugs

Answer 7

1) bronchodilators
2) anti inflammatory drugs

Question 8

bronchodilators types

Answer 8

• b2 adrenergic agonists (salbutamol)
• anticholinergics (ipratropium bromide)
• xanthine derivatives (theophylline/aminophylline)

Question 9

anti inflammatory drug types

Answer 9

• glucocorticoids (budesonide, fluticasone, combination therapy - advair diskus)
• leukotriene modifiers (montelukast)

Question 10

bronchodilators (b agonists)

Answer 10

• sympathomimetic bronchodilators
• acts like epi that bind to b2 to relax smooth muscle in bronchi
• short acting b agonists (SABA)
• long acting b agonists

used more for asthma than COPD

Question 11

selective b2 drugs

Answer 11

activate airway smooth muscle b2 adrenergic receptors
- salbutamol (SABA - quick relief of asthma symptoms when needed, prophylactic before exercise or a known attack)
- salmeterol (LABA)
- formoterol (LABA)

Question 12

b agonists mechanism of action

Answer 12

dilation of airways by activating smooth muscle b2 receptors
- relax bronchial smooth muscle (dilation)
- increase airflow

Question 13

b agonist indications

Answer 13

used for relief of bronchospasm related to asthma, COPD, and other pulmonary diseases (symptomatic relief)
- treatment of acute attacks
- prevent attacks: chronic management, exercise-induced (not used every day to control, only for specific cases like exercise)

Question 14

b agonists adverse effects

Answer 14

• cardiac stimulation/tachycardia: may bind to b1 receptors and increase HR and FOC (could be problematic in pt with underlying heart problem, heart working harder and increase angina attack)
• tremors: acting on b receptors in skeletal muscles, less likely to maintain solid contraction of muscles
• restlessness, insomnia, anxiety (CNS stimulation): beta receptors on neurons in brain

most common in salbutamol
- more likely when given PO bc whole body exposed to drug

Question 15

b agonists nursing implications

Answer 15

• avoid triggers
• adequate fluid intake (thinner mucus, easier to clear)
• monitor for therapeutic effects (decreased dyspnea, decreased wheezing, restlessness, and anxiety, increased respirations and quality, improved activity tolerance)

Question 16

anticholinergics mechanism of action

Answer 16

more common in COPD than asthma
- antagonist
- against muscarinic receptors on bronchial smooth muscle
- Ach causes constriction of bronchial smooth muscle and anticholinergic drug blocks this action so airways relax and open up

Question 17

anticholinergic example

Answer 17

ipratropium
- prevent bronchoconstriction (fixed schedule use for maintenance)
- not used alone for acute exacerbations (not fast enough)
- inhaled drug (local effect)

Question 18

anticholinergic adverse effects

Answer 18

• dry mouth/throat (cough): molecules stay in mouth and effect PNS nerves to lower salivary secretion
• systemic effects minimal (doesn’t absorb in other areas)

Question 19

methylxanthines example

Answer 19

• theophylline (PO)
• aminophylline (IV)

asthma treatment

Question 20

methylxanthines mechanism of action

Answer 20

not clear how it works
- increased cell cAMP
- anti inflammatory
- adenosine receptor antagonist

causes bronchial smooth muscle relaxations, quick relief of bronchospasm for greater airflow in and out of lungs

Question 21

xanthine derivatives indications

Answer 21

-mild to moderate cases of acute asthma
- adjunct agent in management of COPD

Question 22

methylxanthines adverse effects

Answer 22

• CNS stimulation: anxiety, insomnia, seizures (uncontrolled AP in brain neurons)
• CV stimulation: palpitations (increased FOC/fast HR), sinus tachycardia, ventricular dysrhythmias, diuresis (increased blood flow to kidneys) this is problematic in preexisting heart problems
• GI distress: N & V

similar effects to caffeine - stimulant

Question 22

methylxanthines interactions

Answer 22

• increased effects of theophylline with ciprofloxacin which inhibits CYP metabolism
• large amounts of caffeine can intensify adverse effects
• decreased effects of theophylline with liver enzyme inducers (antiseizure drugs) which increase metabolism

Question 23

methylxanthines care implications

Answer 23

encourage reporting: palpitations, N&V, weakness, dizziness, chest pain, convulsions

Question 24

anti inflammatory drugs: glucocorticoids general info

Answer 24

taken daily to deal with symptoms (not acute relief)
- many drugs in this group
- similar action to cortisol
- high doses are immunosuppressive
- steroid drug with structure based on cholesterol
- anti inflammatory
- inhaled: for chronic asthma and COPD
- inhaled form reduces systemic effects
- may take several weeks for full therapeutic effect

Question 25

glucocorticoids mechanism of action

Answer 25

many mechanisms:
- reduce inflammatory mediators (pgs, lts, etc)
- decrease production of cytokines
- reduce infiltration and activity of inflammatory cells (eosinophils and other leukocytes)
- reduces edema (capillary permeability)

Question 26

inhaled glucocorticoid examples

Answer 26

• budesonide
• beclomethasone
• mometasone
• fluticasone

combination preparations
- glucocorticoid +LABA
- budesonide + formoterol
- fluticasone + salmeterol (advair diskus)
- mometasone + formoterol

Question 27

inhaled glucocorticoids indications

Answer 27

prophylaxis treatment of asthma and COPD (with LABA)
- preventative
- taken everyday
- control symptoms

Question 28

inhaled glucocorticoids adverse effects

Answer 28

• oral fungal infections (dampen immune response in mouth)
• pharyngeal irritation
• coughing
• dry mouth

high adverse effects when not inhaled - immunosuppressant

Question 29

care implications inhaled glucocorticoids

Answer 29

• avoid if candida in sputum
• may slow growth in children but doesn’t reduce adult height
• possible bone loss
• use b agonist inhaler before glucocorticoid
• rinse mouth to avoid fungal infection

Question 30

anti inflammatory drugs: leukotriene modulators

Answer 30

for asthma
- all given PO

Question 31

what are leukotrienes

Answer 31

released in immune response in asthma

cause:
- inflammation
- bronchoconstriction
- mucus production
- leukocyte recruitment
- coughing, wheezing, SOB

Question 32

what do leukotriene modulators do?

Answer 32

suppress leukotriene effects:
- suppress smooth muscle contraction of bronchiole
- decrease mucus
- prevent vascular permeability
- decrease neutrophil and other leukocyte infiltration to the lungs, preventing inflammation
- relieving asthma symptoms

Question 33

leukotriene modulator examples

Answer 33

leukotriene receptor antagonists:
- montelukast (generally well tolerated)
- zafirlukast (liver injury and CYP inhibition)

leukotriene synthesis inhibitor
- zileuton (liver injury and CYP inhibition)

Question 34

leukotriene modulator indications

Answer 34

prophylaxis and chronic treatment of asthma in adults and children
- montelukast in children ages 2 and older
- daily management

not for acute asthma attacks

Question 35

leukotriene modulators nursing implications

Answer 35

use on continuous schedule for chronic management of asthma (not acute)

improvement should be seen in 1 day - 1 week