Drugs Affecting the Respiratory System

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Drugs Affecting the Respiratory System

• Bronchodilators and Other Respiratory Drugs

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Respiratory System DrugsLower Respiratory Tract
Diseases

• Asthma
• Emphysema
• Chronic bronchitis

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Respiratory System DrugsAsthma

• Recurrent and reversible shortness of breath
• Airways become narrow as a result of
• Bronchospasm
• Inflammation Edema of the bronchial mucosa
• Production of viscid mucus
• Alveolar ducts/alveoli remain open, but airflow
  to them is obstructed
• Symptoms
• Wheezing
• Difficulty breathing

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Respiratory System DrugsAsthma

• 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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Respiratory System DrugsChronic Bronchitis

• Continuous inflammation of the bronchi and
  bronchioles
• Often occurs as a result of prolonged exposure to
  bronchial irritants
• Characterized by
• Hypoxemia
• Chronic productive cough
• Blue Bloater

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Respiratory System DrugsEmphysema

• 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
• Characterized by
• Increased paCO2 - respiratory acidosis
• Difficulty exhaling pursed lip breathing
• Pink Puffer

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Respiratory System DrugsCOPD Drugs

• Long-term control
• Antileukotrienes
• cromolyn
• Inhaled steroids
• Long-acting ß2-agonists
• Quick relief
• Intravenous systemic corticosteroids
• Short-acting inhaled ß2-agonists

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Respiratory System Drugs

• Bronchodilators
• ß-adrenergic agonists
• Xanthine derivatives
• Anticholinergics
• Antileukotrienes
• Corticosteroids

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Respiratory System DrugsBronchodilators
ß-Agonists

• Large group, sympathomimetics
• Used during acute phase of asthmatic attacks
• Quickly reduce airway constriction
• Stimulate ß2-adrenergic receptors throughout the
  lungs

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Respiratory System Drugs Bronchodilators
ß-Agonists

• Three types
• Nonselective adrenergics
• Stimulate a, ß1 (cardiac), and ß2 (respiratory)
  receptors
• Example epinephrine
• Nonselective ß-adrenergics
• Stimulate both ß1 and ß2 receptors
• Example metaproterenol
• Selective ß2 drugs
• Stimulate only ß2 receptors
• Example albuterol (Proventil)

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Respiratory System DrugsBronchodilators
ß-Agonists

• Mechanism of Action
• Begins at the specific receptor stimulated
• Ends with the dilation of the airways
• Activation of ß2 receptors activates cAMP,
  which relaxes smooth muscles of the airway and
  results in bronchial dilation and increased
  airflow
• cAMP cyclic adenosine monophosphate

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Respiratory System DrugsBronchodilators
ß-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
• Hyperkalemiastimulates potassium to shift into
  the cell

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Respiratory System Drugsß-Agonists Adverse
Effects

• a-ß (epinephrine)
• Insomnia
• Restlessness
• Anorexia
• Vascular headache

• Hyperglycemia
• Tremor
• Cardiac stimulation

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Respiratory System Drugsß-Agonists Adverse
Effects

• ß1 and ß2 (metaproterenol)
• Cardiac stimulation
• Tremor
• Anginal pain

• Vascular headache
• Hypotension

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Respiratory System Drugsß-Agonists Adverse
Effects

• ß2 (albuterol)
• Hypotension OR hypertension
• Vascular headache
• Tremor

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Respiratory System Drugs ß-Agonists Nursing
Implications

• Thorough assessment before beginning therapy
• Skin color
• Baseline vital signs
• Respirations (should be between 12 and 24
  breaths/min)
• Respiratory assessment, including PO2
• Sputum production
• Allergies
• History of respiratory problems
• Other medications

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Respiratory System Drugs ß-Agonists - 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
• Patients should know how to use inhalers and MDIs
• Have patients demonstrate use of devices
• Monitor for adverse effects

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Respiratory System Drugs ß-Agonists - Patient
Education

• Patients should be encouraged to have a good
  state of health
• 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
• Patients to get prompt treatment for flu or other
  illnesses
• Patients to get vaccinated against pneumonia and
  flu
• Check with their physician before taking any
  medication, including OTCs
• Teach patients to take bronchodilators exactly as
  prescribed

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Respiratory System Drugsß-Agonist
DerivativesNsg Implications

• Albuterol, if used too frequently, loses its
  ß2-specific actions at larger doses
• As a result, ß1 receptors are stimulated, causing
  nausea, increased anxiety, palpitations, tremors,
  and increased heart rate
• Take medications exactly as prescribed
• No omissions or double doses
• Report insomnia, jitteriness, restlessness,
  palpitations, chest pain, or any change in
  symptoms

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InhalersPatient 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
• Ensure that patient knows how to keep track of
  the number of doses in the inhaler device

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Respiratory System
DrugsAnticholinergics

• 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
• ipratropium bromide (Atrovent) and tiotropium
  (Spiriva)
• Slow and prolonged action
• Used to prevent bronchoconstriction
• NOT used for acute asthma exacerbations!

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Respiratory System DrugsAnticholinergics

• Adverse effects
• Dry mouth or throat
• Nasal congestion
• Heart palpitations
• Gastrointestinal distress
• Headache
• Coughing
• Anxiety
• No known drug interactions

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Respiratory System DrugsBronchodilatorsXanthine
Derivatives

• Plant alkaloids
• caffeine, theobromine, and theophylline
• Only theophylline is used as a bronchodilator
• Synthetic xanthines
• (IV) theophylline (Aminophylline)
• (oral) theophylline (Elixophyllin, Theo-Dur)

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Respiratory System Drugs BronchodilatorsXanthin
e Derivatives

• Increase levels of energy-producing cAMP
• This is done competitively inhibiting
  phosphodiesterase (PDE), the enzyme that breaks
  down cAMP (cAMP cyclic adenosine monophosphate)
• Result
• decreased cAMP levels, smooth muscle relaxation,
  bronchodilation, and increased airflow
• 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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Respiratory System Drugs BronchodilatorsXanthin
e Derivatives

• Dilate of airways in asthma, chronic bronchitis,
  and emphysema
• Mild to moderate cases of acute asthma
• Adjunct drug in the management of COPD
• Not used as frequently due to
• potential for drug interactions
• 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, extrasystoles, 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 (causes gastric irritation)
• Report to physician
• Palpitations Nausea Vomiting
  
• Weakness Dizziness Chest pain
• Convulsions
• Interactions with cimetidine, oral
  contraceptives, allopurinol, certain antibiotics
  elevate serum xanthine blood levels
• Nicotine caffeine potentiate cardiac effects
• St. Johns wort increases metabolism decrease
  blood levels

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Respiratory System DrugsAntileukotrienes

• Also called
• leukotriene receptor antagonists (LRTAs)
• Newer class of asthma drugs
• Currently available drugs
• montelukast (Singulair)
• zafirlukast (Accolate)
• zileuton (Zyflo)

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Respiratory System Drugs Antileukotrienes

• Leukotrienes
• substances released when a trigger, such as cat
  hair or dust, starts a series of chemical
  reactions in the body
• cause inflammation, bronchoconstriction, and
  mucus production
• Result coughing, wheezing, shortness of breath

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Respiratory System DrugsMechanism of Action

• Antileukotriene drugs
• prevent leukotrienes from attaching to
  receptors on cells in and in circulation
• Inflammation in the lungs is blocked
• Asthma symptoms are relieved
• 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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Respiratory System Drugs 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,
  and for treatment of allergic rhinitis

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Respiratory System DrugsAntileukotrienes
Adverse Effects

• zileuton (Zyflo) zafirlukast (Accolate)
• Headache Headache
• Dyspepsia Nausea
• Nausea Diarrhea
• Dizziness Liver dysfunction
• Insomnia
• Liver dysfunction
• Montelukast (Singulair) has fewer adverse
  effects

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Respiratory System DrugsNursing Implications
Pt Ed

• 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
• Check with physician before taking any OTC or
  prescribed medicationsmany 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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Respiratory System DrugsCorticosteroids

• Anti-inflammatory!!!
• Uses - chronic asthma/COPD exacerbations
• Do not relieve acute asthmatic attacks SS
• Oral, IV (quick acting), or inhaled forms
• Inhaled forms reduce systemic effects
• May take several weeks before full effects are
  seen

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Respiratory System DrugsCorticosteroids

• Mechanism of Action
• Stabilize membranes of cells that release harmful
  bronchoconstricting substances
• Also increase responsiveness of bronchial smooth
  muscle to ß-adrenergic stimulation

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Respiratory System Drugs Inhaled Corticosteroids

• beclomethasone dipropionate (Beclovent,
  Vanceril)
• triamcinolone acetonide (Azmacort)
• dexamethasone sodium phosphate (Decadron
  Phosphate Respihaler)
• fluticasone (Flovent, Flonase)

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Respiratory System DrugsCorticosteroids -
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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Respiratory System DrugsCorticosteroids -
Adverse Effects

• 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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Corticosteroids Nursing Implications Pt
Education

• 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
• If a ß-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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Corticosteroids Nursing Implications Pt
Education

• Teach patients
• to monitor disease with a peak flow meter
• use of a spacer device to ensure successful
  inhalations
• keep inhalers and nebulizer equipment clean after
  uses
• Tapering doses of oral corticosteroids

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Review

• Doses of xanthine derivatives may need to be
  reduced in older adult patients. True or false?
  Explain your answer.
•  2. The therapeutic blood level of theophylline
  in the adult is _____________
• 3. Theophylline is classified as a
  _____________ _____________, whereas albuterol
  (Proventil) and epinephrine (Medinhaler-Epi) are
  _____________________ ______________.
•  
• 4. ß-agonists are contraindicated in patients
  with _________ or _________ disorders.
•  
• Antileukotriene drugs reduce _______________
  associated with asthma, and are used for
  chronic/acute asthma.
• 6. This antileukotriene drug is US Food and Drug
  Administration (FDA) approved for use in children
  2 years of age and older ___________________.

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Review Answers

• Lower doses in the older adult may be necessary
  initially and during therapy with close
  monitoring for adverse effects and toxicity
  (cardiovascular and central nervous system CNS
  stimulation).
• 2. The therapeutic blood level of theophylline
  in the adult is 10 to 20 mcg/mL some
  practitioners recommend 5 to 15 mcg/mL
• 3. Theophylline is classified as a xanthine
  derivative, whereas albuterol and epinephrine are
  ß-agonist bronchodilators.
•  
• 4. ß-agonists are contraindicated in patients
  with a high risk of stroke or any cardiovascular
  disorders, particularly tachydysrhythmias.
•  
• 5. Antileukotriene drugs reduce inflammation
  associated with asthma, and are used for chronic
  asthma.
• 6. This antileukotriene drug is US Food and Drug
  Administration (FDA) approved for use in children
  2 years of age and older montelukast
  (Singulair).
•  

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Review

• For each drug listed, state whether it is used
  for
•  
• A. Asthma prophylaxis and maintenance treatment
• B. Treatment of acute bronchospasm
• C. Both
• 1. montelukast (Singulair), an antileukotriene
• 2. theophylline (Theo-Dur) oral tablets,
  xanthine-derived
• 3. fluticasone (Flovent), a synthetic
  glucocorticoid
• 4. ipratropium (Atrovent), an anticholinergic
•  
• 5. albuterol Proventil) inhaler, a ß1 agonist
• 6. epinephrine, intravenous dose, an alpha-beta
  agonist

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Review Answers

• A
• A (not used as much now for relief of acute
  symptoms, especially the oral form)
• A
• C
• C
• 6. B (for the IV form)