Respi drugs


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Respi drugs

  1. 1. Drugs affecting the respiratory system
  2. 2. Objectives1. Antihistamines2. Decongestants3. Antitussives4. Expectorants5. Bronchodilators6. Beta adrenergic agonist7. Anticholinergics8. Antileukotriene agents9. Corticosteroids10. Mast cell stablizers
  3. 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. 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. 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. 6. Antihistamines Drugs that directly compete with histamine for specific receptor sites Two histamine receptors  H1 (histamine1)  H2 (histamine2)
  7. 7. Antihistamines (cont’d)H1 histamine receptor- found on smooth muscle,endothelium, and central nervous system tissue; causesvasodilation, bronchoconstriction, smooth muscle activation,and separation of endothelia cellss (responsible for hives), andpain and itching due to insect stingsH1 antagonists are commonly referred to asantihistamines Antihistamines have several properties  Antihistaminic  Anticholinergic  Sedative
  8. 8. Antihistamines (cont’d) H2 blockers or H2 antagonists  Used to reduce gastric acid in PUD  Examples: cimetidine, ranitidine, famotidine
  9. 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. 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. 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. 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. 13. Antihistamines: IndicationsManagement of: Nasal allergies Seasonal or perennial allergic rhinitis (hay fever) Allergic reactions Motion sickness Sleep disorders
  14. 14. Antihistamines: Indications (cont’d)Also used to relieve symptoms associated withthe common cold Sneezing, runny nose Palliative treatment, not curative
  15. 15. Antihistamines: Side effects Anticholinergic (drying) effects, most common  Dry mouth  Difficulty urinating  Constipation  Changes in vision Drowsiness  Mild drowsiness to deep sleep
  16. 16. Antihistamines: Two Types Traditional Nonsedating/peripherally acting
  17. 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. 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. 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. 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. 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. 22. Decongestants
  23. 23. Nasal Congestion Excessive nasal secretions Inflamed and swollen nasal mucosa Primary causes  Allergies  Upper respiratory infections (common cold)
  24. 24. Decongestants: Types (cont’d)Two dosage forms Oral Inhaled/topically applied to the nasal membranes
  25. 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. 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. 27. Topical Nasal Decongestants (cont’d) Adrenergics  desoxyephedrine  phenylephrine Intranasal steroids  beclomethasone dipropionate  flunisolide  fluticasone
  28. 28. Nasal Decongestants: Mechanism of ActionSite of action: blood vessels surrounding nasalsinuses 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. 29. Nasal Decongestants: Mechanism of Action (cont’d)Site of action: blood vessels surrounding nasalsinuses 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. 30. Nasal Decongestants: IndicationsRelief of nasal congestion associated with: Acute or chronic rhinitis Common cold Sinusitis Hay fever Other allergies
  31. 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. 32. Nasal Decongestants: Side EffectsAdrenergics SteroidsNervousness Local mucosal drynessInsomnia and irritationPalpitationsTremors(systemic effects due toadrenergic stimulation of theheart, blood vessels, and CNS)
  33. 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. 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. 35. Antitussives
  36. 36. Cough PhysiologyRespiratory secretions and foreign objects arenaturally removed by the: Cough reflex  Induces coughing and expectoration  Initiated by irritation of sensory receptors in the respiratory tract
  37. 37. Two Basic Types of Cough Productive cough  Congested, removes excessive secretions Nonproductive cough  Dry cough
  38. 38. CoughingMost of the time, coughing is beneficial Removes excessive secretions Removes potentially harmful foreign substancesIn some situations, coughing can be harmful, such asafter hernia repair surgery
  39. 39. CoughingMost of the time, coughing is beneficial Removes excessive secretions Removes potentially harmful foreign substancesIn some situations, coughing can be harmful, such asafter hernia repair surgery
  40. 40. Antitussives: DefinitionDrugs used to stop or reduce coughing Opioid and nonopioid (narcotic and nonnarcotic) Used only for nonproductive coughs!
  41. 41. Antitussives: Mechanism of ActionOpioids Suppress the cough reflex by direct action on the cough centre in the medulla Examples:  codeine  hydrocodone
  42. 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. 43. Antitussives: IndicationsUsed to stop the cough reflex when the coughis nonproductive and/or harmful
  44. 44. Antitussives: Side EffectsDextromethorphan Dizziness, drowsiness, nauseaOpioids Sedation, nausea, vomiting, lightheadedness, constipation
  45. 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. 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. 47. Expectorants
  48. 48. Expectorants: Definition Drugs that aid in the expectoration (removal) of mucus Reduce the viscosity of secretions Disintegrate and thin secretions
  49. 49. Expectorants: Mechanisms of Action Direct stimulation Reflex stimulation Final result: thinner mucus that is easier to remove
  50. 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: guaifenesinDirect 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. 51. Expectorants: Drug EffectsBy loosening and thinning sputum andbronchial secretions, the tendency to cough isindirectly diminished
  52. 52. Expectorants: IndicationsUsed for the relief of nonproductive coughsassociated with:Common cold PertussisBronchitis InfluenzaLaryngitis MeaslesPharyngitisCoughs caused by chronic paranasal sinusitis
  53. 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. 54. CHAPTER 36Bronchodilators and Other Respiratory Agents
  55. 55. Table 36-2 Stepwise approach to the management of asthma
  56. 56. Table 36-3 Mechanisms of anti-asthmatic drug action
  57. 57. Diseases of the Lower Respiratory Tract Bronchial asthma Emphysema Chronic bronchitis COPD Cystic fibrosis Acute respiratory distress syndrome
  58. 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. 59. Bronchodilators and Respiratory Agents Bronchodilators  Xanthine derivatives  Beta-adrenergic agonists Anticholinergics Antileukotrienes Corticosteroids Mast cell stabilizers
  60. 60. Bronchodilators: Xanthine Derivatives Plant alkaloids: caffeine, theobromine, and theophylline Only theophylline is used as a bronchodilator  Examples: aminophylline Theophylline Slo-Bid® Uniphyl®
  61. 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. 62. Xanthine Derivatives: Drug Effects (cont’d)Also cause cardiovascular stimulation:increased force of contraction and increasedHR, resulting in increased cardiac output andincreased blood flow to the kidneys (diureticeffect)
  63. 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. 64. Xanthine Derivatives: Side Effects Nausea, vomiting, anorexia Gastroesophageal reflux during sleep Sinus tachycardia, extrasystole, palpitations, ventricular dysrhythmias Transient increased urination
  65. 65. Nursing Implications: Xanthine Derivatives Contraindications: history of PUD or GI disorders Cautious use: cardiac disease
  66. 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. 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. 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. 69. Beta-Agonists: Side EffectsBeta2 (salbutamol) Hypotension OR hypertension Vascular headaches Tremor Contraindicated: clients with allergies, tachyarythmias, severe cardiac disease
  70. 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. 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. 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. 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. 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. 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. 76. Anticholinergics (cont’d)Side effects: Dry mouth or throat Gastrointestinal distress Headache Coughing Anxiety No known drug interactions
  77. 77. Antileukotrienes Also called leukotriene receptor antagonists (LRTAs) Newer class of asthma medications Three subcategories of agents
  78. 78. Antileukotrienes (cont’d)Currently available agents: Montelukast (sold as Singulair®) Zafirlukast (sold as Accolate®)
  79. 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. 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. 81. Antileukotrienes: Drug EffectsBy 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. 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. 83. Antileukotrienes: Side Effects zafirlukast montelukast has fewer Headache side effects Nausea Diarrhea Liver dysfunction
  84. 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. 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. 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. 87. Inhaled Corticosteroids Budesonide (Pulmicort®) Fluticasone (Flovent®)
  88. 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. 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. 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. 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. 92. PO corticosteroids Prednisolone (sold as Pediapred®) Prednisone (sold as Deltasone®)
  93. 93. Combination Medications Some pharmaceutical manufacturers have combined two controller medications into one inhaler. These inhalers are referred to as "Combination Medications".
  94. 94. Combination medications Combination ® Corticosteroids Budesonide (Pumicort®) Formoterol (Oxeze®) Long-Acting bronchodilator Fluticasone (Flovent®) Salmeterol (Severent®)
  95. 95. Mast Cell Stabilizers Cromoglycate (sold as Intal®) Nedocromil (sold as Tilade®) Ketotifen fumarate (sold as Zaditen®)
  96. 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. 97. Mast Cell Stabilizers: Side EffectsCoughing Taste changesSore throat DizzinessRhinitis HeadacheBronchospasm
  98. 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. 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. 100. Client Education Metered Dose Inhaler MDI Spacers Diskus Turbuhaler Nebulized
  101. 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. 102. Spacers should always be used with MDIs that deliver inhaledcorticosteroids. Spacers can make it easier for medication to reach thelungs, and also mean less medication gets deposited in the mouth andthroat, 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. 103. END OF LECTURE