Chapter 37 - The Red Zone

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CHAPTER 37
Bronchodilators and Other
Respiratory Drugs
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Diseases of the Lower
Respiratory Tract

COPD



Asthma
Emphysema
Chronic bronchitis
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Bronchial Asthma


Recurrent and reversible shortness of breath
Occurs when the airways of the lungs
become narrow as a result of:

Bronchospasms
 Inflammation of the bronchial mucosa
 Edema of the bronchial mucosa
 Production of viscid mucus
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Bronchial Asthma (cont’d)


Alveolar ducts/alveoli remain open, but
airflow to them is obstructed
Symptoms


Wheezing
Difficulty breathing
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Asthma

Three categories



Allergic
Idiopathic
Mixed allergic-idiopathic
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Asthma (cont’d)

Status asthmaticus



Prolonged asthma attack that does not respond to
typical drug therapy
May last several minutes to hours
Medical emergency
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Chronic Bronchitis


Continuous inflammation of the bronchi and
bronchioles
Often occurs as a result of prolonged
exposure to bronchial irritants
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Emphysema



Air spaces enlarge as a result of the
destruction of alveolar walls
The surface area where gas exchange takes
place is reduced
Effective respiration is impaired
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Drugs Used to Treat Asthma

Long-term control




Leukotriene receptor antagonists
Inhaled steroids
Long-acting beta2-agonists
Quick relief


Intravenous systemic corticosteroids
Short-acting inhaled beta2-agonists
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Bronchodilators and
Respiratory Drugs

Bronchodilators





Beta-adrenergic agonists
Xanthine derivatives
Anticholinergics
Leukotriene receptor antagonists
Corticosteroids
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Bronchodilators: Beta-Agonists




Large group, sympathomimetics
Used during acute phase of asthmatic attacks
Quickly reduce airway constriction and
restore normal airflow
Stimulate beta2-adrenergic receptors
throughout the lungs
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Bronchodilators: Beta-Agonists
(cont’d)
Three types
 Nonselective adrenergics



Stimulate alpha, beta1 (cardiac), and beta2
(respiratory) receptors
Example: epinephrine
Nonselective beta-adrenergics


Stimulate both beta1 and beta2 receptors
Example: metaproterenol (Alupent)
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Bronchodilators:
Beta-Agonists (cont’d)
Three types (cont’d)
 Selective beta2 drugs


Stimulate only beta2 receptors
Example: albuterol (Proventil, others)
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Beta-Agonists:
Mechanism of Action


Begins at the specific receptor stimulated
Ends with dilation of the airways

Activation of beta2 receptors activates cyclic
adenosine monophosphate (cAMP), which relaxes
smooth muscle in the airway and results in
bronchial dilation and increased airflow
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Beta-Agonists: Indications




Relief of bronchospasm related to asthma,
bronchitis, and other pulmonary diseases
Used in treatment and prevention of acute
attacks
Used in hypotension and shock
Used to produce uterine relaxation to prevent
premature labor
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Beta-Agonists: Adverse Effects

Alpha and beta (epinephrine)







Insomnia
Restlessness
Anorexia
Vascular headache
Hyperglycemia
Tremor
Cardiac stimulation
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Beta-Agonists: Adverse Effects
(cont’d)

Beta1 and beta2 (metaproterenol)

Cardiac stimulation
 Tremor
 Anginal pain
 Vascular headache
 Hypotension
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Beta-Agonists: Adverse Effects
(cont’d)

Beta2 (albuterol)

Hypotension OR hypertension
 Vascular headache
 Tremor
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Nursing Implications

Encourage patients to take measures that
promote a generally good state of health so
as to prevent, relieve, or decrease symptoms
of COPD

Avoid exposure to conditions that precipitate
bronchospasm (allergens, smoking, stress, air
pollutants)
 Adequate fluid intake
 Compliance with medical treatment
 Avoid excessive fatigue, heat, extremes in
temperature, caffeine
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Nursing Implications (cont’d)


Encourage patients to get prompt treatment
for flu or other illnesses, and to get
vaccinated against pneumonia or flu
Encourage patients to always check with their
physician before taking any other medication,
including over-the-counter medications
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Nursing Implications (cont’d)

Perform a thorough assessment before
beginning therapy, including:

Skin color
 Baseline vital signs
 Respirations (should be between 12 and 24
breaths/min)
 Respiratory assessment, including pulse oximetry
 Sputum production
 Allergies
 History of respiratory problems
 Other medications
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Nursing Implications (cont’d)



Teach patients to take bronchodilators
exactly as prescribed
Ensure that patients know how to use
inhalers and MDIs, and have patients
demonstrate use of the devices
Monitor for adverse effects
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Nursing Implications (cont’d)

Monitor for therapeutic effects





Decreased dyspnea
Decreased wheezing, restlessness, and anxiety
Improved respiratory patterns with return to
normal rate and quality
Improved activity tolerance
Decreased symptoms and increased
ease of breathing
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Nursing Implications (cont’d)

Beta-agonist derivatives


Albuterol, if used too frequently, loses its
beta2-specific actions at larger doses
As a result, beta1 receptors are stimulated,
causing nausea, increased anxiety, palpitations,
tremors, and increased heart rate
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Nursing Implications (cont’d)

Beta-agonist derivatives (cont’d)


Ensure that patients take medications exactly
as prescribed, with no omissions or double doses
Inform patients to report insomnia, jitteriness,
restlessness, palpitations, chest pain, or
any change in symptoms
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Inhalers: Patient Education

For any inhaler prescribed, ensure that the
patient is able to self-administer the
medication




Provide demonstration and return demonstration
Ensure that the patient knows the correct time
intervals for inhalers
Provide a spacer if the patient has difficulty
coordinating breathing with inhaler activation
Ensure that the patient knows how to keep track of
the number of doses in the inhaler device
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Anticholinergics




Ipratropium bromide (Atrovent) and tiotropium
(Spiriva)
Slow and prolonged action
Used to prevent bronchoconstriction
NOT used for acute asthma exacerbations!
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Anticholinergics:
Mechanism of Action



Acetylcholine (ACh) causes bronchial
constriction and narrowing of the airways
Anticholinergics bind to the ACh receptors,
preventing ACh from binding
Result: bronchoconstriction is prevented,
airways dilate
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Anticholinergics: Adverse Effects








Dry mouth or throat
Nasal congestion
Heart palpitations
Gastrointestinal distress
Headache
Coughing
Anxiety
No known drug interactions
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Bronchodilators:
Xanthine Derivatives



Plant alkaloids: caffeine, theobromine, and
theophylline
Only theophylline is used as a bronchodilator
Synthetic xanthines: aminophylline and
dyphilline
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Xanthine Derivatives:
Mechanism of Action



Increase levels of energy-producing cAMP
This is done competitively inhibiting
phosphodiesterase (PDE), the enzyme that
breaks down cAMP
Result: decreased cAMP levels, smooth
muscle relaxation, bronchodilation, and
increased airflow
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Xanthine Derivatives:
Drug Effects

Also cause cardiovascular stimulation:
increased force of contraction and increased
heart rate, resulting in increased cardiac
output and increased blood flow to the
kidneys (diuretic effect)
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Xanthine Derivatives:
Drug Effects (cont’d)



Cause bronchodilation by relaxing smooth
muscle in the airways
Result: relief of bronchospasm and greater
airflow into and out of the lungs
Also cause CNS stimulation
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Xanthine Derivatives:
Indications




Dilation of airways in asthmas, chronic
bronchitis, and emphysema
Mild to moderate cases of acute asthma
Adjunct drug in the management of COPD
Not used as frequently because of potential
for drug interactions and variables related to
drug levels in the blood
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Xanthine Derivatives:
Adverse Effects




Nausea, vomiting, anorexia
Gastroesophageal reflux during sleep
Sinus tachycardia, extrasystole, palpitations,
ventricular dysrhythmias
Transient increased urination
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Xanthine Derivatives: Nursing
Implications



Contraindications: history of PUD or
GI disorders
Cautious use: cardiac disease
Timed-release preparations should not be
crushed or chewed (cause gastric irritation)
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Xanthine Derivatives: Nursing
Implications (cont’d)

Report to physician:







Palpitations
Weakness
Convulsions
Nausea
Dizziness
Vomiting
Chest pain
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Xanthine Derivatives: Nursing
Implications (cont’d)

Be aware of drug interactions with cimetidine,
oral contraceptives, allopurinol, certain
antibiotics, others
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Leukotriene Receptor
Antagonists (LTRAs)


Newer class of asthma medications
Currently available drugs



montelukast (Singulair)
zafirlukast (Accolate)
zileuton (Zyflo)
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LRTAs:
Mechanism of Action



Leukotrienes are substances released when
a trigger, such as cat hair or dust, starts a
series of chemical reactions in the body
Leukotrienes cause inflammation,
bronchoconstriction, and mucus production
Result: coughing, wheezing, shortness
of breath
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LRTAs:
Mechanism of Action (cont’d)


LRTAs prevent leukotrienes from attaching to
receptors on cells in the lungs and in
circulation
Inflammation in the lungs is blocked, and
asthma symptoms are relieved
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LRTAs:
Drug Effects

By blocking leukotrienes:




Prevent smooth muscle contraction of the
bronchial airways
Decrease mucus secretion
Prevent vascular permeability
Decrease neutrophil and leukocyte infiltration
to the lungs, preventing inflammation
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LRTAs: Indications



Prophylaxis and chronic treatment of asthma
in adults and children older than age 12
NOT meant for management of acute
asthmatic attacks
Montelukast is approved for use in children
ages 2 and older, and for treatment of allergic
rhinitis
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LRTAs: Adverse Effects

Zileuton


Zafirlukast


Headache, dyspepsia, nausea, dizziness,
insomnia, liver dysfunction
Headache, nausea, diarrhea, liver dysfunction
Montelukast has fewer adverse effects
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LRTAs:
Nursing Implications



Ensure that the drug is being used for chronic
management of asthma, not acute asthma
Teach the patient the purpose of the therapy
Improvement should be seen in about
1 week
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LRTAs:
Nursing Implications (cont’d)



Advise patients to check with physician
before taking over-the-counter or prescribed
medications—there are many drug
interactions
Assess liver function before beginning
therapy
Teach patient to take medications every night
on a continuous schedule, even if symptoms
improve
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Corticosteroids




Antiinflammatory properties
Used for chronic asthma
Do not relieve symptoms of acute
asthmatic attacks
Oral or inhaled forms


Inhaled forms reduce systemic effects
May take several weeks before full
effects are seen
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Corticosteroids:
Mechanism of Action

Stabilize membranes of cells that release
harmful bronchoconstricting substances


These cells are called leukocytes, or white
blood cells
Increase responsiveness of bronchial smooth
muscle to beta-adrenergic stimulation
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Inhaled Corticosteroids





beclomethasone dipropionate
(Beclovent, Vanceril)
triamcinolone acetonide (Azmacort)
dexamethasone sodium phosphate
(Decadron Phosphate Respihaler)
fluticasone (Flovent, Flonase)
Others
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Inhaled Corticosteroids:
Indications


Treatment of bronchospastic disorders
that are not controlled by conventional
bronchodilators
NOT considered first-line drugs for
management of acute asthmatic attacks
or status asthmaticus
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Inhaled Corticosteroids:
Adverse Effects





Pharyngeal irritation
Coughing
Dry mouth
Oral fungal infections
Systemic effects are rare because low doses
are used for inhalation therapy
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Inhaled Corticosteroids:
Nursing Implications


Contraindicated in patients with psychosis,
fungal infections, AIDS, TB
Teach patients to gargle and rinse the mouth
with lukewarm water afterward to prevent the
development of oral fungal infections
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Inhaled Corticosteroids:
Nursing Implications (cont’d)

If a beta-agonist bronchodilator and
corticosteroid inhaler are both ordered, the
bronchodilator should be used several
minutes before the corticosteroid to provide
bronchodilation before administration of the
corticosteroid
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Inhaled Corticosteroids:
Nursing Implications (cont’d)



Teach patients to monitor disease with a
peak flow meter
Encourage use of a spacer device to ensure
successful inhalations
Teach patient how to keep inhalers and
nebulizer equipment clean after uses
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