1. CHAPTER 37 Bronchodilators and Other Respiratory Drugs

2. Diseases of the Lower Respiratory Tract
COPD
Asthma
Emphysema
Chronic bronchitis

3. 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

4. Bronchial Asthma (cont’d)
Alveolar ducts/alveoli remain open, but airflow to them is obstructed
Symptoms
Wheezing
Difficulty breathing

5. Asthma
Three categories
Allergic
Idiopathic
Mixed allergic-idiopathic

6. Asthma (cont’d) Status asthmaticus
Prolonged asthma attack that does not respond to typical drug therapy
May last several minutes to hours
Medical emergency

7. Chronic Bronchitis
Continuous inflammation of the bronchi and bronchioles
Often occurs as a result of prolonged exposure to bronchial irritants

8. 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

9. Drugs Used to Treat Asthma
Long-term control
Leukotriene receptor antagonists
Inhaled steroids
Long-acting beta2-agonists
Quick relief
Intravenous systemic corticosteroids
Short-acting inhaled beta2-agonists

10. Bronchodilators and Respiratory Drugs
Beta-adrenergic agonists
Xanthine derivatives
Anticholinergics
Leukotriene receptor antagonists
Corticosteroids

12. 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

13. Bronchodilators: Beta-Agonists (cont’d)
Three types
Nonselective adrenergics
Stimulate alpha, beta1 (cardiac), and beta2 (respiratory) receptors
Example: epinephrine
Nonselective beta-adrenergics
Stimulate both beta1 and beta2 receptors
Example: metaproterenol (Alupent)

14. Bronchodilators: Beta-Agonists (cont’d)
Three types (cont’d)
Selective beta2 drugs
Stimulate only beta2 receptors
Example: albuterol (Proventil, others)

15. Beta-Agonists: Mechanism of Action
Begins at the specific receptor stimulated
Ends with dilation of the airways
Activation of beta2 receptors activates cyclic adenosine monophosphate (cAMP), which relaxes smooth muscle in the airway and results in bronchial dilation and increased airflow

16. Beta-Agonists: Indications
Relief of bronchospasm related to asthma, bronchitis, and other pulmonary diseases
Used in treatment and prevention of acute attacks
Used in hypotension and shock
Used to produce uterine relaxation to prevent premature labor

17. Beta-Agonists: Adverse Effects
Alpha and beta (epinephrine)
Insomnia
Restlessness
Anorexia
Vascular headache
Hyperglycemia
Tremor
Cardiac stimulation

18. Beta-Agonists: Adverse Effects (cont’d)
Beta1 and beta2 (metaproterenol)
Cardiac stimulation
Tremor
Anginal pain
Vascular headache
Hypotension

19. Beta-Agonists: Adverse Effects (cont’d)
Beta2 (albuterol)
Hypotension OR hypertension
Vascular headache
Tremor

20. Nursing Implications
Encourage patients to take measures that promote a generally good state of health so as to prevent, relieve, or decrease symptoms of COPD
Avoid exposure to conditions that precipitate bronchospasm (allergens, smoking, stress, air pollutants)
Adequate fluid intake
Compliance with medical treatment
Avoid excessive fatigue, heat, extremes in temperature, caffeine

21. Nursing Implications (cont’d)
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 over-the-counter medications

22. Nursing Implications (cont’d)
Perform a thorough assessment before beginning therapy, including:
Skin color
Baseline vital signs
Respirations (should be between 12 and 24 breaths/min)
Respiratory assessment, including pulse oximetry
Sputum production
Allergies
History of respiratory problems
Other medications

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

24. 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

25. Nursing Implications (cont’d)
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

26. Nursing Implications (cont’d)
Beta-agonist derivatives (cont’d)
Ensure that patients take medications exactly as prescribed, with no omissions or double doses
Inform patients to report insomnia, jitteriness, restlessness, palpitations, chest pain, or any change in symptoms

27. Inhalers: Patient Education
For any inhaler prescribed, ensure that the patient is able to self-administer the medication
Provide demonstration and return demonstration
Ensure that the patient knows the correct time intervals for inhalers
Provide a spacer if the patient has difficulty coordinating breathing with inhaler activation
Ensure that the patient knows how to keep track of the number of doses in the inhaler device

28. Anticholinergics
Ipratropium bromide (Atrovent) and tiotropium (Spiriva)
Slow and prolonged action
Used to prevent bronchoconstriction
NOT used for acute asthma exacerbations!

29. 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

30. Anticholinergics: Adverse Effects
Dry mouth or throat
Nasal congestion
Heart palpitations
Gastrointestinal distress
Headache
Coughing
Anxiety
No known drug interactions

31. Bronchodilators: Xanthine Derivatives
Plant alkaloids: caffeine, theobromine, and theophylline
Only theophylline is used as a bronchodilator
Synthetic xanthines: aminophylline and dyphilline

32. Xanthine Derivatives: Mechanism of Action
Increase levels of energy-producing cAMP
This is done competitively inhibiting phosphodiesterase (PDE), the enzyme that breaks down cAMP
Result: decreased cAMP levels, smooth muscle relaxation, bronchodilation, and increased airflow

33. Xanthine Derivatives: Drug Effects
Also cause cardiovascular stimulation: increased force of contraction and increased heart rate, resulting in increased cardiac output and increased blood flow to the kidneys (diuretic effect)

34. Xanthine Derivatives: Drug Effects (cont’d)
Cause bronchodilation by relaxing smooth muscle in the airways
Result: relief of bronchospasm and greater airflow into and out of the lungs
Also cause CNS stimulation

35. Xanthine Derivatives: Indications
Dilation of airways in asthmas, chronic bronchitis, and emphysema
Mild to moderate cases of acute asthma
Adjunct drug in the management of COPD
Not used as frequently because of potential for drug interactions and variables related to drug levels in the blood

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

37. Xanthine Derivatives: Nursing Implications
Contraindications: history of PUD or GI disorders
Cautious use: cardiac disease
Timed-release preparations should not be crushed or chewed (cause gastric irritation)

38. Xanthine Derivatives: Nursing Implications (cont’d)
Report to physician:
Palpitations
Weakness
Convulsions
Nausea
Dizziness
Vomiting
Chest pain

39. Xanthine Derivatives: Nursing Implications (cont’d)
Be aware of drug interactions with cimetidine, oral contraceptives, allopurinol, certain antibiotics, others

40. Leukotriene Receptor Antagonists (LTRAs)
Newer class of asthma medications
Currently available drugs
montelukast (Singulair)
zafirlukast (Accolate)
zileuton (Zyflo)

41. LRTAs: 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

42. LRTAs: Mechanism of Action (cont’d)
LRTAs 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

43. LRTAs: 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

44. LRTAs: 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 2 and older, and for treatment of allergic rhinitis

45. LRTAs: Adverse Effects
Zileuton
Headache, dyspepsia, nausea, dizziness, insomnia, liver dysfunction
Zafirlukast
Headache, nausea, diarrhea, liver dysfunction
Montelukast has fewer adverse effects

46. LRTAs: 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

47. LRTAs: Nursing Implications (cont’d)
Advise patients to check with physician before taking over-the-counter or prescribed medications—there are many drug interactions
Assess liver function before beginning therapy
Teach patient to take medications every night on a continuous schedule, even if symptoms improve

48. Corticosteroids Antiinflammatory properties 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

49. Corticosteroids: Mechanism of Action
Stabilize membranes of cells that release harmful bronchoconstricting substances
These cells are called leukocytes, or white blood cells
Increase responsiveness of bronchial smooth muscle to beta-adrenergic stimulation

50. Inhaled Corticosteroids
beclomethasone dipropionate (Beclovent, Vanceril)
triamcinolone acetonide (Azmacort)
dexamethasone sodium phosphate (Decadron Phosphate Respihaler)
fluticasone (Flovent, Flonase)
Others

51. Inhaled Corticosteroids: 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

52. Inhaled Corticosteroids: Adverse Effects
Pharyngeal irritation
Coughing
Dry mouth
Oral fungal infections
Systemic effects are rare because low doses are used for inhalation therapy

53. Inhaled Corticosteroids: Nursing Implications
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

54. Inhaled Corticosteroids: Nursing Implications (cont’d)
If a beta-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

55. Inhaled Corticosteroids: Nursing Implications (cont’d)
Teach patients to monitor disease with a peak flow meter
Encourage use of a spacer device to ensure successful inhalations
Teach patient how to keep inhalers and nebulizer equipment clean after uses