Transcript Pharmacology and the Nursing Process, 4th ed. Lilley

CHAPTER 36
Bronchodilators and Other
Respiratory Agents
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Diseases of the Lower
Respiratory Tract
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Bronchial asthma
Emphysema
Chronic bronchitis
COPD
Cystic fibrosis
Infant respiratory distress syndrome
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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 usual medical therapy
– 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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COPD
Chronic obstructive pulmonary disease
• Applies to chronic bronchitis and
emphysema
• Obstruction is constant
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Agents Used to Treat Asthma
• Long-term control
– Antileukotrienes
– Ipratropium
– Cromolyn
– Nedocromil
– Inhaled steroids
– theophylline
– Long-acting beta2-agonists
• Quick relief
– Intravenous systemic corticosteroids
– Short-acting inhaled beta2-agonists
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Bronchodilators and
Respiratory Agents
• Bronchodilators
– Xanthine derivatives
– Beta-adrenergic agonists
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Anticholinergics
Antileukotrienes
Corticosteroids
Mast cell stabilizers
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Bronchodilators:
Xanthine Derivatives
• Plant alkaloids: caffeine, theobromine, and
theophylline
• Only theophylline is used as a bronchodilator
– Examples:
• Aminophylline
• Dyphilline
• Oxtriphylline
• theophylline (Bronkodyl, Slo-bid, TheoDur, Uniphyl)
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Xanthines: Action
• Smooth muscle relaxation
• Bronchodilation
• Increased airflow
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Xanthines: Drug Effects
CNS stimulation
Cardiovascular stimulation:
increased force of contraction
increased HR
increased cardiac output
increased blood flow to the kidneys (diuretic
effect)
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Xanthines: Indications
• Dilation of airways in asthmas, chronic
bronchitis, and emphysema
• Mild to moderate cases of acute asthma
• Adjunct agent in the management of
COPD
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Xanthines: Side Effects
• Nausea, vomiting, anorexia
• Gastroesophageal reflux during sleep
• Sinus tachycardia, extrasystole,
palpitations, ventricular dysrhythmias
• Transient increased urination
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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
Three types
• Nonselective adrenergics
– Stimulate alpha-, beta1- (cardiac), and
beta2- (respiratory) receptors
– Example: epinephrine
• Nonselective beta-adrenergics
– Stimulate both beta1- and beta2-receptors
– Example: isoproterenol (Isuprel)
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Bronchodilators:
Beta-Agonists (cont'd)
Three types (cont'd)
• Selective beta2 drugs
– Stimulate only beta2-receptors
– Example: albuterol
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Beta-Agonists:
Mechanism of Action
• Begins at the specific receptor
stimulated
• Ends with the dilation of the airways
– relaxes smooth muscles of 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
• Useful in treatment of acute attacks as well
as prevention
• Used in hypotension and shock
• Used to produce uterine relaxation to prevent
premature labor
• Hyperkalemia—stimulates potassium to shift
into the cell
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Beta-Agonists: Side Effects
Alpha-Beta
• insomnia
• restlessness
• anorexia
• vascular headache
(epinephrine)
• hyperglycemia
• tremor
• cardiac stimulation
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Beta-Agonists: Side Effects
Beta1 and Beta2 (isoproterenol)
• Cardiac stimulation
• Hypotension
• Anginal pain
• Tremor
• Vascular headaches
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Beta-Agonists: Side Effects
Beta2 (albuterol)
• Hypotension OR hypertension
• Vascular headaches
• Tremor
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Nursing Implications
• Encourage patients to take measures that
promote a generally good state of health in
order to prevent, relieve, or decrease
symptoms of COPD
– Avoid exposure to conditions that precipitate
bronchospasms (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
• 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 OTCs
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Nursing Implications
• Perform a thorough assessment before
beginning therapy, including:
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Skin color
Baseline vital signs
Respirations (should be <12 or >24 breaths/min)
Respiratory assessment, including PO2
Sputum production
Allergies
History of respiratory problems
Other medications
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Nursing Implications
• Teach patients to take bronchodilators
exactly as prescribed
• Ensure that patients know how to use
inhalers and MDIs, and have the
patients demonstrate use of devices
• Monitor for side effects
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Nursing Implications
• 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:
Xanthine Derivatives
• Contraindications: history of PUD or
GI disorders
• Cautious use: cardiac disease
• Timed-release preparations should not
be crushed or chewed (causes gastric
irritation)
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Nursing Implications:
Xanthine Derivatives
• Report to physician:
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Palpitations
Nausea
Vomiting
Weakness
– Dizziness
– Chest pain
– Convulsions
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Nursing Implications:
Xanthine Derivatives
• Be aware of drug interactions with
cimetidine, oral contraceptives,
allopurinol
• Large amounts of caffeine can have
deleterious effects
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Nursing Implications:
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:
Beta-Agonist Derivatives
• Patients should take medications
exactly as prescribed, with no omissions
or double doses
• Patients should 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 the patient knows the correct time intervals
for inhalers
– Provide a spacer if the patient has difficulty
coordinating breathing with inhaler activation
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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
• ipratropium bromide (Atrovent) is the
only anticholinergic used for respiratory
disease
• Slow and prolonged action
• Used to prevent bronchoconstriction
• NOT used for acute asthma
exacerbations!
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Anticholinergics (cont'd)
Side effects:
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Dry mouth or throat
Gastrointestinal distress
Headache
Coughing
Anxiety
No known drug interactions
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Antileukotrienes
• Also called leukotriene receptor
antagonists (LRTAs)
• Newer class of asthma medications
• Three subcategories of agents
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Antileukotrienes (cont'd)
Currently available agents
– montelukast (Singulair)
– zafirlukast (Accolate)
– zileuton (Zyflo)
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Leukotrienes
Substances in the body that cause
inflammation, bronchoconstriction, and
mucus production
• Result: coughing, wheezing, shortness
of breath
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Antileukotrienes:
Mechanism of Action
• Prevent inflammation in the lungs so
asthma symptoms are relieved
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Antileukotrienes: Drug Effects
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Keep bronchial airways relaxed (open)
Decrease mucus secretion
Prevent vascular permeability
Preventing inflammation
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Antileukotrienes: Indications
• Prophylaxis and chronic treatment of
asthma in adults and children older than
age 12
• NOT meant for management of acute
asthmatic attacks
• Montelukast (Singulair) is approved for
use in children ages 2 and older
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Antileukotrienes: Side Effects
zileuton
zafirlukast
Headache
Headache
Dyspepsia
Nausea
Nausea
Diarrhea
Dizziness
Liver dysfunction
Insomnia
Liver dysfunction
• montelukast has fewer side effects
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Antileukotrienes:
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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Antileukotrienes:
Nursing Implications
• Check with physician before taking any
OTC or prescribed medications—many
drug interactions
• Assess liver function before beginning
therapy
• Medications should be taken every night on a
continuous schedule, even if symptoms
improve
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Corticosteroids
• Antiinflammatory
• 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 leukocytes, or white
blood cells
• Also 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)
• flunisolide (AeroBid)
• fluticasone (Flovent, Flonase)
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Inhaled Corticosteroids:
Indications
• Treatment of bronchospastic disorders
that are not controlled by conventional
bronchodilators
• NOT considered first-line agents for
management of acute asthmatic attacks
or status asthmaticus
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Inhaled Corticosteroids:
Side Effects
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Pharyngeal irritation
Coughing
Dry mouth
Oral fungal infections
• Systemic effects are rare because of
the low doses used for inhalation
therapy
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Inhaled Corticosteroids:
Nursing Implications
• Contraindicated in patients with psychosis,
fungal infections, AIDS, TB
• Cautious use in patients with diabetes,
glaucoma, osteoporosis, PUD, renal disease,
HF, edema
• Teach patients to gargle and rinse the mouth
with water afterward to prevent the
development of oral fungal infections
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Inhaled Corticosteroids:
Nursing Implications
• Abruptly discontinuing these medications can
lead to serious problems
• If discontinuing, should be weaned for 1 to 2
weeks, only if recommended by physician
• Report any weight gain of more than 5
pounds a week or the occurrence of chest
pain
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Mast Cell Stabilizers
• cromolyn (NasalCrom, Intal)
• nedocromil (Tilade)
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Mast Cell Stabilizers (cont'd)
• Indirect-acting agents that prevent the
release of the various substances that cause
bronchospasm
• Stabilize the cell membranes of
inflammatory cells (mast cells, monocytes,
macrophages), thus preventing release of
harmful cellular contents
• No direct bronchodilator activity
• Used prophylactically
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Mast Cell Stabilizers:
Indications
• Adjuncts to the overall management of
asthma
• Used solely for prophylaxis, NOT for
acute asthma attacks
• Used to prevent exercise-induced
bronchospasm
• Used to prevent bronchospasm associated
with exposure to known precipitating factors,
such as cold, dry air or allergens
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Mast Cell Stabilizers:
Side Effects
Coughing
Sore throat
Rhinitis
Bronchospasm
Taste changes
Dizziness
Headache
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Mast Cell Stabilizers:
Nursing Implications
• For prophylactic use only
• Contraindicated for acute exacerbations
• Not recommended for children younger than
age 5
• Therapeutic effects may not be seen for up to
4 weeks
• Teach patients to gargle and rinse the mouth
with water afterward to minimize irritation to
the throat and oral mucosa
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