1. Drugs affecting the respiratory
system

2. Objectives
1. Antihistamines
2. Decongestants
3. Antitussives
4. Expectorants
5. Bronchodilators
6. Beta adrenergic agonist
7. Anticholinergics
8. Antileukotriene agents
9. Corticosteroids
10. Mast cell stablizers

3. Understanding the Common
Cold
 Most caused by viral infection
(rhinovirus or influenza virus—the “flu”)
 Virus invades tissues (mucosa) of upper respiratory
tract, causing upper respiratory infection (URI)

4. Treatment of the
Common Cold
 Involves combined use of antihistamines, nasal
decongestants, antitussives, and expectorants
 Treatment is symptomatic only, not curative
 Symptomatic treatment does not eliminate the
causative pathogen

5. Treatment of the
Common Cold (cont’d)
 Difficult to identify whether cause is viral or
bacterial
 Treatment is “empiric therapy,” treating the most
likely cause
 Antivirals and antibiotics may be used, but a
definite viral or bacterial cause may not be easily
identified

6. Antihistamines
Drugs that directly compete with histamine
for specific receptor sites
 Two histamine receptors
 H1 (histamine1)
 H2 (histamine2)

7. Antihistamines (cont’d)
H1 histamine receptor- found on smooth muscle,
endothelium, and central nervous system tissue; causes
vasodilation, bronchoconstriction, smooth muscle activation,
and separation of endothelia cellss (responsible for hives), and
pain and itching due to insect stings
H1 antagonists are commonly referred to as
antihistamines
 Antihistamines have several properties
 Antihistaminic
 Anticholinergic
 Sedative

8. Antihistamines (cont’d)
 H2 blockers or H2 antagonists
 Used to reduce gastric acid in PUD
 Examples: cimetidine, ranitidine, famotidine

9. Antihistamines (cont’d)
 10% to 20% of general population is sensitive to
various environmental allergies
 Histamine-mediated disorders
 Allergic rhinitis (hay fever, mould and dust allergies)
 Anaphylaxis
 Angioneurotic edema
 Drug fevers
 Insect bite reactions
 Urticaria (itching)

10. Antihistamines:
Mechanism of Action
 Block action of histamine at the H1 receptor sites
 Compete with histamine for binding at unoccupied
receptors
 Cannot push histamine off the receptor if already
bound

11. Antihistamines:
Mechanism of Action (cont’d)
 The binding of H1 blockers to the histamine
receptors prevents the adverse consequences of
histamine stimulation
 Vasodilation
 Increased GI and respiratory secretions
 Increased capillary permeability

12. Antihistamines:
Mechanism of Action (cont’d)
 More effective in preventing the actions of
histamine rather than reversing them
 Should be given early in treatment, before all
the histamine binds to the receptors

13. Antihistamines: Indications
Management of:
 Nasal allergies
 Seasonal or perennial allergic rhinitis
(hay fever)
 Allergic reactions
 Motion sickness
 Sleep disorders

14. Antihistamines: Indications
(cont’d)
Also used to relieve symptoms associated with
the common cold
 Sneezing, runny nose
 Palliative treatment, not curative

15. Antihistamines: Side effects
 Anticholinergic (drying) effects, most
common
 Dry mouth
 Difficulty urinating
 Constipation
 Changes in vision
 Drowsiness
 Mild drowsiness to deep sleep

16. Antihistamines: Two Types
 Traditional
 Nonsedating/peripherally acting

17. Traditional Antihistamines
 Older
 Work both peripherally and centrally
 Have anticholinergic effects, making them
more effective than nonsedating agents in
some cases
 Examples: Benedryl (diphenhydramine)

18. Nonsedating/Peripherally
Acting Antihistamines
 Developed to eliminate unwanted side
effects, mainly sedation
 Work peripherally to block the actions of
histamine; thus, fewer CNS side effects
 Longer duration of action (increases
compliance)
 Examples: reactine, allegra

19. Antihistamines:
Nursing Implications
 Gather data about the condition or allergic reaction
that required treatment; also assess for drug
allergies
 Contraindicated in the presence of acute asthma
attacks and lower respiratory diseases
 Use with caution in increased intraocular pressure,
cardiac or renal disease, hypertension, asthma,
COPD, peptic ulcer disease, BPH, or pregnancy

20. Antihistamines:
Nursing Implications (cont’d)
 Instruct clients to report excessive sedation,
confusion, or hypotension
 Avoid driving or operating heavy machinery,
and do not consume alcohol or other CNS
depressants
 Do not take these medications with other
prescribed or OTC medications without
checking with prescriber

21. Antihistamines:
Nursing Implications (cont’d)
 Best tolerated when taken with meals—
reduces GI upset
 If dry mouth occurs, teach client to perform
frequent mouth care, chew gum, or suck on
hard candy to ease discomfort
 Monitor for intended therapeutic effects

22. Decongestants

23. Nasal Congestion
 Excessive nasal secretions
 Inflamed and swollen nasal mucosa
 Primary causes
 Allergies
 Upper respiratory infections (common cold)

24. Decongestants: Types (cont’d)
Two dosage forms
 Oral
 Inhaled/topically applied to the nasal membranes

25. Oral Decongestants
 Prolonged decongestant effects,
but delayed onset
 Effect less potent than topical
 No rebound congestion
 Exclusively adrenergics
 Example: pseudoephedrine, Sinutab, Dristan,
Tylenol cold, Sudafed

26. Topical Nasal Decongestants
 Topical adrenergics
 Prompt onset
 Potent
 Sustained use over several days causes rebound
congestion, making the condition worse
 Eg:
DRISTAN* DECONGESTANT NASAL MIST (SOLUTION)
COMPOSITION:
Each 1 mL of solution contains:
Phenylephrine HCl 5 mg
Pheniramine Maleate 2 mg

27. Topical Nasal
Decongestants (cont’d)
 Adrenergics
 desoxyephedrine
 phenylephrine
 Intranasal steroids
 beclomethasone dipropionate
 flunisolide
 fluticasone

28. Nasal Decongestants:
Mechanism of Action
Site of action: blood vessels surrounding nasal
sinuses
 Adrenergics
 Constrict small blood vessels that supply
URI structures
 As a result these tissues shrink, and nasal secretions in
the swollen mucous membranes are better able to drain
 Nasal stuffiness is relieved

29. Nasal Decongestants:
Mechanism of Action (cont’d)
Site of action: blood vessels surrounding nasal
sinuses
 Nasal steroids
 Anti-inflammatory effect
 Work to turn off the immune system cells involved
in the inflammatory response
 Decreased inflammation results in decreased congestion
 Nasal stuffiness is relieved

30. Nasal Decongestants:
Indications
Relief of nasal congestion associated with:
 Acute or chronic rhinitis
 Common cold
 Sinusitis
 Hay fever
 Other allergies

31. Nasal Decongestants:
Indications (cont’d)
 May also be used to reduce swelling of the
nasal passage and facilitate visualization of
the nasal/pharyngeal membranes before
surgery or diagnostic procedures

32. Nasal Decongestants:
Side Effects
Adrenergics Steroids
Nervousness Local mucosal dryness
Insomnia and irritation
Palpitations
Tremors
(systemic effects due to
adrenergic stimulation of the
heart, blood vessels, and CNS)

33. Nasal Decongestants:
Nursing Implications
 Decongestants may cause hypertension,
palpitations, and CNS stimulation—avoid in
clients with these conditions
 Clients on medication therapy for
hypertension should check with their
physician before taking OTC decongestants
 Assess for drug allergies

34. Nasal Decongestants:
Nursing Implications (cont’d)
 Clients should avoid caffeine and caffeine-
containing products
 Report a fever, cough, or other symptoms lasting
longer than a week
 Monitor for intended therapeutic effects

35. Antitussives

36. Cough Physiology
Respiratory secretions and foreign objects are
naturally removed by the:
 Cough reflex
 Induces coughing and expectoration
 Initiated by irritation of sensory receptors in the
respiratory tract

37. Two Basic Types of Cough
 Productive cough
 Congested, removes excessive secretions
 Nonproductive cough
 Dry cough

38. Coughing
Most of the time, coughing is beneficial
 Removes excessive secretions
 Removes potentially harmful foreign substances
In some situations, coughing can be harmful, such as
after hernia repair surgery

39. Coughing
Most of the time, coughing is beneficial
 Removes excessive secretions
 Removes potentially harmful foreign substances
In some situations, coughing can be harmful, such as
after hernia repair surgery

40. Antitussives: Definition
Drugs used to stop or reduce coughing
 Opioid and nonopioid
(narcotic and nonnarcotic)
 Used only for nonproductive coughs!

41. Antitussives:
Mechanism of Action
Opioids
 Suppress the cough reflex by direct action on the
cough centre in the medulla
Examples:
 codeine
 hydrocodone

42. Antitussives:
Mechanism of Action (cont’d)
Nonopioids
 Suppress the cough reflex by numbing the
stretch receptors in the respiratory tract and
preventing the cough reflex from being
stimulated
Examples:
 Dextromethorphan, Nyquil, Robitussin

43. Antitussives: Indications
Used to stop the cough reflex when the cough
is nonproductive and/or harmful

44. Antitussives: Side Effects
Dextromethorphan
 Dizziness, drowsiness, nausea
Opioids
 Sedation, nausea, vomiting, lightheadedness,
constipation

45. Antitussive Agents:
Nursing Implications
 Perform respiratory and cough assessment,
and assess for allergies
 Instruct clients to avoid driving or operating
heavy equipment due to possible sedation,
drowsiness, or dizziness
 If taking chewable tablets or lozenges,
do not drink liquids for 30 to 35 minutes
afterward

46. Antitussive Agents:
Nursing Implications (cont’d)
 Report any of the following symptoms to the
caregiver
 Cough that lasts more than a week
 A persistent headache
 Fever
 Rash
 Antitussive agents are for nonproductive coughs
 Monitor for intended therapeutic effects

47. Expectorants

48. Expectorants: Definition
 Drugs that aid in the expectoration
(removal) of mucus
 Reduce the viscosity of secretions
 Disintegrate and thin secretions

49. Expectorants:
Mechanisms of Action
 Direct stimulation
 Reflex stimulation
Final result: thinner mucus
that is easier to remove

50. Expectorants:
Mechanism of Action (cont’d)
Reflex stimulation
 Agent causes irritation of the GI tract
 Loosening and thinning of respiratory tract secretions occur
in response to this irritation
 Example: guaifenesin
Direct stimulation
 The secretory glands are stimulated directly to increase their
production of respiratory tract fluids
 Examples: iodine-containing products such as iodinated
glycerol and potassium iodide

51. Expectorants: Drug Effects
By loosening and thinning sputum and
bronchial secretions, the tendency to cough is
indirectly diminished

52. Expectorants: Indications
Used for the relief of nonproductive coughs
associated with:
Common cold Pertussis
Bronchitis Influenza
Laryngitis Measles
Pharyngitis
Coughs caused by chronic paranasal sinusitis

53. Expectorants:
Nursing Implications
 Expectorants should be used with caution in the
elderly or those with asthma or respiratory
insufficiency
 Clients taking expectorants should receive more
fluids, if permitted, to help loosen and liquefy
secretions
 Report a fever, cough, or other symptoms lasting
longer than a week
 Monitor for intended therapeutic effects

54. CHAPTER 36
Bronchodilators and Other
Respiratory Agents

55. Table 36-2 Stepwise approach to the management of asthma

56. Table 36-3 Mechanisms of anti-asthmatic drug action

57. Diseases of the Lower
Respiratory Tract
 Bronchial asthma
 Emphysema
 Chronic bronchitis
 COPD
 Cystic fibrosis
 Acute respiratory distress syndrome

58. Agents Used to Treat Asthma
 Long-term control
 Antileukotrienes
 ipratropium
 Cromoglycate
 nedocromil
 Inhaled steroids  theophylline
 Long-acting beta2-agonists
 Quick relief
 Intravenous systemic corticosteroids
 Short-acting inhaled beta2-agonists

59. Bronchodilators and
Respiratory Agents
 Bronchodilators
 Xanthine derivatives
 Beta-adrenergic agonists
 Anticholinergics
 Antileukotrienes
 Corticosteroids
 Mast cell stabilizers

60. Bronchodilators:
Xanthine Derivatives
 Plant alkaloids: caffeine, theobromine, and
theophylline
 Only theophylline is used as a bronchodilator
 Examples:
aminophylline
Theophylline
Slo-Bid®
Uniphyl®

61. Xanthine Derivatives:
Drug Effects
 Cause bronchodilation by relaxing smooth muscles
of the airways
 Result: relief of bronchospasm and greater airflow
into and out of the lungs
 Also cause CNS stimulation
 Slow onset action and are mostly used for
prevention
 Aminophylline(Status asthmaticus)

62. Xanthine Derivatives:
Drug Effects (cont’d)
Also cause cardiovascular stimulation:
increased force of contraction and increased
HR, resulting in increased cardiac output and
increased blood flow to the kidneys (diuretic
effect)

63. Xanthine Derivatives:
Indications
 Dilation of airways in asthmas, chronic
bronchitis, and emphysema
 Mild to moderate cases of acute asthma
 Adjunct agent in the management of COPD

64. Xanthine Derivatives:
Side Effects
 Nausea, vomiting, anorexia
 Gastroesophageal reflux during sleep
 Sinus tachycardia, extrasystole, palpitations,
ventricular dysrhythmias
 Transient increased urination

65. Nursing Implications:
Xanthine Derivatives
 Contraindications: history of PUD or
GI disorders
 Cautious use: cardiac disease

66. 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

67. Bronchodilators: Beta-Agonists
(cont’d)
Three types
 Nonselective adrenergics
 Stimulate alpha-, beta - (cardiac), and beta - (respiratory) receptors
1 2
Example: epinephrine
 Nonselective beta-adrenergics
 Stimulate both beta - and beta -receptors
1 2
 Example: isoproterenol
 Selective beta2 drugs
 Stimulate only beta2-receptors
 Example: salbutamol

68. Beta-Agonists: Indications
 Relief of bronchospasm related to asthma,
bronchitis, and other pulmonary diseases
 Useful in treatment of acute attacks as well
as prevention

69. Beta-Agonists: Side Effects
Beta2 (salbutamol)
 Hypotension OR hypertension
 Vascular headaches
 Tremor
 Contraindicated: clients with allergies,
tachyarythmias, severe cardiac disease

70. Nursing Implications
 Encourage clients 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

71. Nursing Implications (cont’d)
 Perform a thorough assessment before beginning
therapy, including:
 Skin colour
 Baseline vital signs
 Respirations (should be <12 or >24 breaths/min)
 Respiratory assessment, including SaO2
 Sputum production
 Allergies
 History of respiratory problems
 Other medications

72. Nursing Implications (cont’d)
 Teach clients to take bronchodilators exactly
as prescribed
 Ensure that clients know how to use inhalers
and MDIs, and have the clients demonstrate
use of devices
 Monitor for side effects

73. 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

74. 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

75. Anticholinergics
 Atrovent (ipratropium bromide) is the only
anticholinergic used for respiratory disease
 Slow and prolonged action
 Used to prevent bronchoconstriction
 NOT used for acute asthma exacerbations!
 Combivent (salbutamol/ipratroprium)

76. Anticholinergics (cont’d)
Side effects:
 Dry mouth or throat
 Gastrointestinal distress
 Headache
 Coughing
 Anxiety
No known drug interactions

77. Antileukotrienes
 Also called leukotriene receptor antagonists
(LRTAs)
 Newer class of asthma medications
 Three subcategories of agents

78. Antileukotrienes (cont’d)
Currently available agents:
 Montelukast (sold as Singulair®)
 Zafirlukast (sold as Accolate®)

79. Antileukotrienes:
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

80. Antileukotrienes:
Mechanism of Action (cont’d)
 Antileukotriene agents 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

81. Antileukotrienes: 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

82. 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 is approved for use in children
ages 6 and older

83. Antileukotrienes: Side Effects
zafirlukast montelukast has fewer
 Headache side effects
 Nausea
 Diarrhea
 Liver dysfunction

84. Antileukotrienes:
Nursing Implications
 Ensure that the drug is being used for chronic
management of asthma, not
acute asthma
 Teach the client the purpose of the therapy
 Improvement should be seen in about
1 week

85. Corticosteroids
 Anti-inflammatory
 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

86. 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

87. Inhaled Corticosteroids
 Budesonide (Pulmicort®)
 Fluticasone (Flovent®)

88. 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

89. Inhaled Corticosteroids:
Side Effects
 Pharyngeal irritation
 Coughing
 Dry mouth
 Oral fungal infections
 Systemic effects are rare because of the low
doses used for inhalation therapy

90. Inhaled Corticosteroids:
Nursing Implications
 Contraindicated in client with psychosis,
fungal infections, AIDS, TB
 Cautious use in clients with diabetes,
glaucoma, osteoporosis, PUD, renal disease,
HF, edema
 Teach clients to gargle and rinse the mouth
with water afterward to prevent the
development of oral fungal infections

91. Inhaled Corticosteroids:
Nursing Implications (cont’d)
 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 2.5 kg a
week or the occurrence of chest pain

92. PO corticosteroids
 Prednisolone (sold as Pediapred®)
 Prednisone (sold as Deltasone®)

93. Combination Medications
 Some pharmaceutical manufacturers have
combined two controller medications into
one inhaler. These inhalers are referred to as
"Combination Medications".

94. Combination medications
 Combination ®
 Corticosteroids
 Budesonide (Pumicort®)
 Formoterol (Oxeze®)
 Long-Acting bronchodilator
 Fluticasone (Flovent®)
 Salmeterol (Severent®)

95. Mast Cell Stabilizers
 Cromoglycate (sold as Intal®)
 Nedocromil (sold as Tilade®)
 Ketotifen fumarate (sold as Zaditen®)

96. 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

97. Mast Cell Stabilizers:
Side Effects
Coughing Taste changes
Sore throat Dizziness
Rhinitis Headache
Bronchospasm

98. 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 clients to gargle and rinse the mouth with
water afterward to minimize irritation to the throat
and oral mucosa

99. Inhalers:
Client Education
 For any inhaler prescribed, ensure that the
client is able to self-administer the
medication
 Provide demonstration and return demonstration
 Ensure the client knows the correct time
intervals for inhalers
 Provide a spacer if the client has difficulty
coordinating breathing with inhaler activation

100. Client Education
 Metered Dose Inhaler MDI
 Spacers
 Diskus
 Turbuhaler
 Nebulized

101. Inhalers fall into two categories
 Aerosol Inhalers: Pressurized metered dose inhaler is a
canister filled with asthma medication suspended in a
propellant. When the canister is pushed down, a measured
dose of the medication is pushed out as you breathe it in.
Pressurized metered dose inhalers are commonly called
"puffers".
 Dry-powder inhalers: Dry powdered inhalers contain a dry
powder medication that is drawn into your lungs when you
breathe in.

102. Spacers should always be used with MDIs that deliver inhaled
corticosteroids. Spacers can make it easier for medication to reach the
lungs, and also mean less medication gets deposited in the mouth and
throat, where it can lead to irritation and mild infections. The Asthma
Society of Canada recommends that anyone, of any age, using a
puffer, consider using a spacer.

103. END OF LECTURE