Drugs affecting the respiratory system

1
Drugs affecting the respiratory system

• Lilley, Harrington,Snyder
• Chapters 35 36

2
Objectives

• Antihistamines
• Decongestants
• Antitussives
• Expectorants
• Bronchodilators
• Beta adrenergic agonist
• Anticholinergics
• Antileukotriene agents
• Corticosteroids
• Mast cell stablizers

3
Understanding the Common Cold

• Most caused by viral infection (rhinovirus or
  influenza virusthe 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 (contd)

• 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 (contd)

• 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 (contd)

• H2 blockers or H2 antagonists
• Used to reduce gastric acid in PUD
• Examples cimetidine, ranitidine, famotidine

9
Antihistamines (contd)

• 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 (contd)

• 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 (contd)

• 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 (contd)

• 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
AntihistaminesNursing 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
AntihistaminesNursing Implications (contd)

• 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
AntihistaminesNursing Implications (contd)

• Best tolerated when taken with mealsreduces 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 (contd)

• 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
• EgDRISTAN DECONGESTANT NASAL MIST
  (SOLUTION)COMPOSITIONEach 1 mL of solution
  contains        Phenylephrine HCl        5
  mg        Pheniramine Maleate        2 mg

27
Topical Nasal Decongestants (contd)

• Adrenergics
• desoxyephedrine
• phenylephrine
• Intranasal steroids
• beclomethasone dipropionate
• flunisolide
• fluticasone

28
Nasal DecongestantsMechanism 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 DecongestantsMechanism of Action (contd)

• 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 (contd)

• 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 theheart, blood vessels, and CNS)

33
Nasal DecongestantsNursing Implications

• Decongestants may cause hypertension,
  palpitations, and CNS stimulationavoid 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 DecongestantsNursing Implications (contd)

• 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 (contd)

• 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 AgentsNursing 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 AgentsNursing Implications (contd)

• 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 (contd)

• 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 Bronchitis Laryngitis Pharyngitis Cou
ghs caused by chronic paranasal sinusitis
Pertussis Influenza Measles
53
ExpectorantsNursing 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 36Bronchodilators 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

• ipratropium
• nedocromil
• theophylline

• Long-term control
• Antileukotrienes
• Cromoglycate
• Inhaled steroids
• 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 (contd)

• 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 (contd)

• 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
• 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 (contd)

• Perform a thorough assessment before beginning
  therapy, including
• Skin colour
• Baseline vital signs
• Respirations (should be lt12 or gt24 breaths/min)
• Respiratory assessment, including SaO2
• Sputum production
• Allergies
• History of respiratory problems
• Other medications

72
Nursing Implications (contd)

• 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 (contd)

• 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 (contd)

• 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 (contd)

• 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, shortnessof breath

80
Antileukotrienes Mechanism of Action (contd)

• 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
• Headache
• Nausea
• Diarrhea
• Liver dysfunction

• montelukast has fewer side effects

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
(contd)

• 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
• Sore throat
• Rhinitis
• Bronchospasm

• Taste changes
• Dizziness
• Headache

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
InhalersClient 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.