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Drugs Acting on the Respiratory System

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					Drugs Acting on the Respiratory System

1

Introduction
 The respiratory system is subject to

many disorders that interfere with respiration and other lung functions, including


  

Respiratory tract infections Allergic disorders Inflammatory disorders Conditions that obstruct airflow (e.g. asthma and chronic obstructive pulmonary disease, COPD)

2

Introduction (Cont’d)
 Drugs that act on the respiratory

system include
 
    

Bronchodilators Corticosteroids Cromoglycates Leukotriene receptor antagonists Antihistamines Cough preparations Nasal decongestants
3

Introduction (Cont’d)
 Drugs acting on the respiratory system,

especially for asthma, can be administered by inhalation, the advantages are:
  

Enhance therapeutic effects Minimize systemic effects Rapid relief of acute attacks

4

 Asthma is a chronic inflammatory disorder of the

airways in which many cells and cellular elements play a role, in particular, mast cells, eosinophils, T lymphocytes, macrophages, neutrophils, and epithelial cells. In susceptible individuals, this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. The inflammation also causes an associated increase in the existing bronchial hyperresponsiveness to a variety of stimuli.
5

The condition of a patient’s asthma may change depending on the environment, activities, and other factors. When the patient is well, monitoring and treatment are still needed to maintain control.

6

Introduction (Cont’d)
 There are various types of inhalation

devices:


Metered-dose inhalers (MDIs)
 Pressurized

devices that deliver a measured dose of drug with each activation  With CFC or non-CFC propellant  Hand-mouth coordination is required

7

Introduction (Cont’d)
 Spacers:
 



Use with MDIs Increase delivery of drug to the lungs & decrease deposition of drug on the oropharyngeal mucosa Especially important for inhaled corticosteroids

8

Introduction (Cont’d)


Dry-powder inhalers (DPIs)
 Include

Turbuhalers & Accuhalers  Drugs are in the form of dry, micronized powder  No propellant is employed  Breath activated, much easier to use

9

Introduction (Cont’d)


Nebulizers
 Small

machine to convert a drug solution into

mist  Droplets in the mist are much finer than those produced by inhalers  Through face mask or mouth piece held between the teeth  Take several minutes to deliver the same amount of drug contained in 1 puff from an inhaler
10

Bronchodilators
 Drugs used to relieve bronchospasms

associated with respiratory disorders  Includes:


Adrenoceptor agonists
 Selective

β2-agonists & other adrenoceptor

agonists
 

Antimuscarinic bronchodilators Xanthine derivatives

11

Bronchodilators (Cont’d)
 Adrenoceptor agonists


(i) Selective beta2 agonists
 Stimulate

beta2 receptors in smooth muscle of the lung, promoting bronchodilation, and thereby relieving bronchospasms  They are divided into short-acting & long acting types

12

Bronchodilators (Cont’d)
Short-acting β-2 agonists
Drug Formulation Dosage

Adult
Salbutamol Oral tablet (C.R) Inhaler (MDI), 100mcg/dose Syrup, 2mg/5ml 8 mg twice daily 100-200mcg up to three to four times daily 4 mg three to four times daily

Child
4 mg twice daily Same as adult 1-2 mg three to four times daily (≥2 yr)

Terbutaline

Oral tablet (S.R)
Inhaler 500mg / dose ( Turbuhaler) Inhaler 250mg / dose (MDI)

5-7.5 mg two times daily
500 mcg up to four times daily 250-500mcg up to 3-4 times daily

Same as adult

13

Bronchodilators (Cont’d)
Long-acting β-2 agonists
Drug Formulation Dosage

Adult Formoterol Inhaler 4.5mcg / dose (Turbuhaer) 4.5-9 mcg once or twice daily

Child Same as adult

Inhaler 9mcg / dose (Turbuhaer) Salmeterol Inhaler 25mcg / dose (MDI) 50-100 mcg twice daily Same as adult

50 mcg / dose (Accuhaler) 50 mcg twice

Same as adult

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Bronchodilators (Cont’d)
 Adverse effects


 

Tachycardia and palpitations Headache Tremor

15

Bronchodilators (Cont’d)


(ii) Other adrenoceptor agonists
 Less

suitable & less safe for use as bronchodilators because they are more likely to cause arrhythmias & other side effects


Ephedrine  Adults: 15-60 mg tid po  Child: 7.5-30 mg tid po

 Adrenaline

(epinephrine) injection is used in the emergency treatment of acute allergic and anaphylactic reactions
16

Bronchodilators (Cont’d)


Nursing Alerts
 When

2 or more puffs are needed, inform the patient that at least 1 minute should be allowed between puffs  Inform the patient that salmeterol and formoterol, and oral β-2 agonists should be taken on a fixed schedule, not on a prn basis  Instruct the patient to report chest pain and changes in heart rhythm or rate, because β-2 agonists can cause cardiac stimulation  Contact physician if symptoms such as nervousness, insomnia, restlessness and tremor become severe
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Bronchodilators (Cont’d)
 Antimuscarinic bronchodilators




Blocks the action of acetylcholine in bronchial smooth muscle, this reduces intracellular GMP, a bronchoconstrictive substance Used for maintenance therapy of bronchoconstriction associated with chronic bronchitis & emphysema

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Bronchodilators (Cont’d)
Drug Formulation
Adult Ipratropium Inhaler 20 mcg / dose (MDI) 20-80 mcg three to four times a day

Dosage
Child 20-40 mcg three to four times a day (≥6yrs)

Tiotropium

Inhaler 18 mcg /dose

18 mcg daily

Not recommended in children and adolescents

19

Bronchodilators (Cont’d)
 Adverse effects:
   

Dry mouth Nausea Constipation Headache

20

Bronchodilators (Cont’d)
 Xanthine Derivatives






Main xanthine used clinically is theophylline Theophylline is a bronchodilator which relaxes smooth muscle of the bronchi, it is used for reversible airway obstruction One proposed mechanism of action is that it acts by inhibiting phosphodiesterase, thereby increasing cAMP, leading to bronchodialtion
21

Bronchodilators (Cont’d)
Drug Formulation Dosage Adult Child

Theophylline

Tablet 200 / 300 mg (S.R.)
Capsule 50 / 100 mg (Slow release)

200 – 300 mg twice daily
7-12 mg/ kg / day in two divided doses

10 mg / kg ((≥2yrs) twice daily
10-16 mg / kg / day in two divided doses (9–16yrs) 13-20 mg / kg / day in two divided doses (30 months – 8 yrs)

Syrup 80 mg / 15 ml

25 ml q6h

1 ml / kg (Max 25 ml) q6h (≥2yrs)
1 mg / kg /hr (6 months – 9 years) 800 mcg / kg /hr (10 – 16 yrs) IV infusion, adjust when necessary
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Aminophylline

Injection 25 mg / ml 10 ml

500 mcg / kg / hr IV infusion, adjust when necessary

Bronchodilators (Cont’d)


Adverse effects:
 Toxicity

is related to theophyline levels (usually 5-15 µg/ml)  20-25 µg/ml : Nausea, vomiting, diarrhea, insomnia, restlessness  >30 µg/ml : Serious adverse effects including dysrhythmias, convulsions, cardiovascular collapse which may result in death

23

Bronchodilators (Cont’d)


Nursing alerts:
 Plasma

theophylline levels should be monitored to keep it in the therapeutic range, usually 5-15 µg/ml. Dosage should be adjusted to keep theophylline levels below 20 µg/ml  If patients miss a dose, the following dose should not be doubled

24

Bronchodilators (Cont’d)


Nursing alerts (Cont’d):
 Instruct

the patient that sustained-release formulations should be swallowed intact  Caution patients in consuming caffeine containing-beverages and other sources of caffeine. Caffeine can intensify the adverse effects and decrease the metabolism of theophylline

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Corticosteroids
 Used for prophylaxis of chronic asthma  Suppressing inflammation


 

Decrease synthesis & release of inflammatory mediators Decrease infiltration & activity of inflammatory cells Decrease edema of the airway mucosa

 Decrease airway mucus production  Increase the number of bronchial beta2

receptors & their responsiveness to beta2 agonists
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Corticosteroids (Cont’d)

Drug

Formulation

Dosage

Adult
Beclomethasone Inhaler 50 mcg / dose (MDI) 200 mcg twice daily / 100mcg three to fours times daily Up to 800 mcg daily

Child
50 – 100 mcg two to four times daily

Inhaler 250 mcg / dose (MDI)

500 mcg twice daily / 250 mcg four times daily

Not recommended

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Corticosteroids (Cont’d)
Drug (Cont’d) Formulation Dosage

Adult Budesonide Inhaler 50 mcg / dose (MDI)
Inhaler 200mcg / dose (MDI) Inhaler 100 mcg / dose (Turbuhaler) 200-800 mcg once daily in evening Up to 1.6 mg daily in two divided doses

Child 50 – 400 mcg twice daily Up to 800 mcg daily

200 mcg twice daily Up to 1.6 mg daily

Inhaler 200 mcg / dose (Turbuhaler)
Inhaler 400 mcg / dose (Turbuhaler)

200-800 mcg daily in two divided doses / 200-400 mcg once daily in evening (<12 yrs)

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Corticosteroids (Cont’d)
Drug (Cont’d) Formulation Dosage

Adult Fluticasone Inhaler 25mcg / dose (MDI) Inhaler 50 mcg / dose (MDI) Inhaler 125 mcg / dose (MDI) Inhaler 250 mcg / dose (MDI)
Inhaler 50 mcg / dose (Accuhaler)

Child 50-100 mcg twice daily (4-16 yrs)

100 – 1000 mcg twice daily

Inhaler 100 mcg / dose (Accuhaler)
Inhaler 250 mcg / dose (Accuhaler)

 Acute

attacks of asthma should be treated with short courses of oral corticosteroids, starting with a high dose for a few days
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Corticosteroids (Cont’d)
 Adverse effects


Inhaled corticosteroids:
 Candidiasis

of the mouth or throat

 Hoarseness  Can

slow growth in children  Adrenal suppression may occur in long-term, high dose therapy  Increases the risk of cataracts

30

Corticosteroids (Cont’d)
 Nursing alerts




Rinse mouth with water without swallowing after administration to reduce the risk of candidiasis If taking bronchodilators by inhalation, use bronchodilators several minutes before the corticosteroid to enhance application of the corticosteroid into the bronchial tract

31

Combination Products
 May be appropriate for patients stabilised on

individual components in the same proportion


Muscarinic antagonist+β2 agonist
 Combivent

(20mcg Ipratropium & 100mcg salbutamol /dose, MDI)



Corticosteroid+β2 agonist
(160mcg Budesonide+4.5mcg Formoterol / dose, Turbuhaler)  Seretide (Salmeterol+Fluticasone: MDi in Lite, Medium, Forte preparation & Accuhaler)
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 Symbicort

Cromoglycates
 Stabilise mast cells & prevent the

release of bronchoconstrictive & inflammatory substances when mast cells are confronted with allergens & other stimuli  Only for prophylaxis of acute asthma attacks

33

Cromoglycates (Cont’d)
Drug Formulation Dosage

Adult Cromoglycate Na Inhaler (1 mg & 5mg/dose)
Nebuliser solution 10 mg / ml 2 ml Nedocromil Sodium Inhaler 2 mg / dose (MDI)

Child Same as adult

10 mg four times daily, may be increased to six to eight times daily
20 mg four times daily, may be increased six times daily

Same as adult

4 mg two to four times daily

Sames as adult (>6 yrs)

34

Cromoglycates (Cont’d)
Adverse effects Nursing Alerts

Transient Bronchospasm

A selective β2 agonist such as salbutamol or terbutaline may be inhaled a few minutes beforehand

Others: coughing, throat irritation

35

Cromoglycates (Cont’d)
 Nursing Alerts (Cont’d)




Cromoglycates are for long-term prophylaxis, patients should administer on a regular schedule & the full therapeutic effects may take several weeks to develop They are contraindicated in patients who are hypersensitive to the drugs

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Leukotriene receptor antagonists
 Act by suppressing the effects of

leukotrienes, compounds that promote bronchoconstriction as well as eosinophil infiltration, mucus productions, & airway edema  Help to prevent acute asthma attacks induced by allergens & other stimuli  Indicated for long-term treatment of asthma
37

Leukotriene receptor antagonists (Cont’d)
 Dosage:


Montelukast (5 & 10 mg tablets)
 Adult:

10 mg daily at bedtime

 Child:

(2-5yrs) 4 mg daily at bedtime  (6-14yrs) 5 mg daily at bedtime


38

Leukotriene receptor antagonists (Cont’d)
 Adverse effects:
    

GI disturbances Hypersensitivity reactions Restlessness & headache Upper respiratory tract infection Manufacturer advises to avoid these drugs in pregnancy & breast-feeding unless essential

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Management of Chronic Asthma for adults & schoolchildren above 5yrs
 Step

1: Occasional relief short-acting beta2 agonist

 Step

2: Add regular preventer therapy Standard-dose inhaled corticosteroid

40

Management of Chronic Asthma for adults & schoolchildren above 5yrs (Cont’d)
3: Add long-acting inhaled beta2 agonist; dose of inhaled corticosteroid may also be increased
 Step

 Step

4: Add high dose of inhaled corticosteroids

41

Management of Chronic Asthma for adults & schoolchildren above 5yrs (Cont’d)

 Step

5: Add regular oral corticosteroid E.g. prednisolone

42

Management of Chronic Asthma for adults & schoolchildren above 5yrs (Cont’d)
 Stepping down:
 

Review treatment every 3 months If symptoms controlled, may initiate stepwise reduction
 Lowest

possible dose oral corticosteroid  Gradual reduction of dose of inhaled corticosteroid to the lowest dose which controls asthma

43

44

Antihistamines
 H1 receptor antagonists


 

Inhibit smooth muscle constriction in blood vessels & respiratory & GI tracts Decrease capillary permeability Decrease salivation & tear formation

 Used for variety of allergic disorders to

prevent or reverse target organ inflammation
45

Antihistamines (Cont’d)
 All antihistamines are of potential value

in the treatment of nasal allergies, particularly seasonal allergic rhinitis (hay fever)  Reduce rhinorrhoea & sneezing but are usually less effective for nasal congestion  Are also used topically in the eye, in the nose, & on the skin
46

Antihistamines (Cont’d)
 First-generation H1 receptor antagonists  Non-selective/sedating  Bind to both central & peripheral H1 receptors  Usually cause CNS depression (drowsiness, sedation) but may cause CNS stimulation (anxiety, agitation), especially in children  Also have substantial anticholinergic effects
47

Antihistamines (Cont’d)
Drug
Chorpheniramine (4 mg tablet, 2mg/ml Elixir & expectorant) Hydroxyzine (25 mg tablet)

Dosage
Adult 4 mg q4-6hr, max: 24 mg daily Child 1-2yrs: 1 mg twice daily 2-12yrs: 1- 2 mg q4-6h, Max:12 mg daily

25 mg at night; 25mg three to four times daily when necessary

6 months-6yrs: 5-15 mg daily; 50 mg daily in divided dose if needed >6yrs: 15-25 mg daily; 50-100 mg daily in divided dose if needed 6.25-25 mg q4-8 hr ( >1 yr)

Diphendramine (10 mg/5ml Elixir)

25-50 mg q4-6h

48

Antihistamines (Cont’d)
Drug (Cont’d) Dosage Adult Promethazine (10 & 25 mg tablets, 5mg/5ml Elixir) 25 mg at night; 25 mg twice daily if needed Child 2-10yrs: 5-25 mg daily in 1 to 2 divided dose

Azatadine (1 mg tablet)

1 mg twice daily

1-12 yrs: 0.25-1 mg twice daily

49

Antihistamines (Cont’d)
 Adverse effects:
      

Sedation Dry mouth Blurred vision GI disturbances Headache Urinary retention Hydroxyzine is not recommended for pregnancy & breast-feeding
50

Antihistamines (Cont’d)
 Second-generation H1 receptor antagonists
 



Selective/non-sedating Cause less CNS depression because they are selective for peripheral H1 receptors & do not cross blood-brain barrier Longer-acting compared to first-generation antihistamines

51

Antihistamines (Cont’d)
Drug Dosage

Adult
Acrivastine (Semprex) 8 mg three times daily

Child
Not recommended

Cetirizine (Zyrtec) Desloratadine (Aerius) Fexofenadine (Telfast)

10 mg daily

5 mg daily / 2.5 mg twice daily (2-6 yrs)

5 mg daily

1.25 mg daily (2-5 yrs) 2.5 mg daily (6-11yrs) Not recommended

120-180 mg daily

Loratadine (Clarityne)

10 mg daily`

5 mg daily (2-5 yrs)

52

Antihistamines (Cont’d)
 Adverse effects:
 

May cause slight sedation Some antihistamines may interact with antifungal, e.g. ketoconazole; antibiotics, e.g. erythromycin; prokinetic drug-cisapride or grapefruit juice, leading to potentially serious ECG changes e.g. Terfenadine

53

Cough preparations
 There are three classes of cough

preparations:
  

Antitussives Expectorants Mucolytics

54

Cough preparations (Cont’d)
 Antitussives
 



Drugs that suppress cough Some act within the CNS, some act peripherally Indicated in dry, hacking, nonproductive cough that interfere with rest & sleep

55

Cough preparations (Cont’d)
Drug Dosage

Codeine phosphate 25mg/5ml syrup

15-30 mg three to four times daily

Pholcodine 5mg/5ml Elixir

5-10 mg three to four times daily

Dextromethorphan 10mg/5ml in Promethazine Compound Linctus Diphenhydramine 10 mg/ 5ml

10-30 mg q4-8h

25 mg q4h, Max:150 mg daily

56

Cough preparations (Cont’d)
 Adverse effects:
 

 

Drowsiness Respiratory depression (for opioid antitussives) Constipation (for opioid antitussives) Preparations containing codeine or similar analgesics are not generally recommended in children & should be avoided altogether in those under 1 year of age
57

Cough preparations (Cont’d)
 Nursing Alerts:


Observe for excessive suppression of the cough reflex (inability to cough effectively when secretions are present). This is a potentially serious adverse effect because retained secretions may lead to lungs collapse, pneumonia, hypoxia, hypercarbia, and respiratory failure

58

Cough preparations (Cont’d)
 Expectorants


 

Render the cough more productive by stimulating the flow of respiratory tract secretions Guaifenesin is most commonly used Available alone & as an ingredient in many combination cough & cold remedies

59

Cough preparations (Cont’d)
 Dosage


Guaifenesin
 100-400

mg q4h po



Ammonia & Ipecacuaha Mixture
 10-20

ml three to four times daily po

60

Cough preparations (Cont’d)
 Mucolytics


Reacts directly with mucus to make it more watery. This should help make the cough more productive

61

Cough preparations (Cont’d)
 Dosage  Acetylcysteine
mg two to four times daily  200 mg two to three times daily  600 mg once daily


 100

Bromhexine
 8-16

mg three times daily po

Carbocisteine
 750

mg three times daily, then 1.5 g daily in divided doses

62

Nasal Decongestants
 Sympathomimetics are used to reduce

nasal congestion  Stimulate alpha1-adrenergic receptors on nasal blood vessels, which causes vasoconstriction & hence shrinkage of swollen membranes

63

Nasal Decongestants (Cont’d)
 Topical administration:


Response is rapid & intense Response are delayed, moderate & prolonged

 Oral administration:


64

Nasal Decongestants (Cont’d)
Drug Formulation Dosage

Adult
Oxymetazoline Nasal Drops 0.025% 20 ml -

Child
2-3 drops q12h (2-5 yrs)

Nasal Spray 0.05% 15 ml

2-3 sprays q12h

Same as adults for children >6 yrs

Phenylephrine

Nasal Drops 0.5% 10 ml

Several drops q2-4h

-

Xylometazoline

Nasal Drops 0.05% / 0.1%

2-3 drops q8-10h (0.1%)

2-3 drops q8-10h (2-12 yrs) (0.05%)

65

Nasal Decongestants (Cont’d)
 Adverse effects:




Rebound congestion develops with topical agents when used for more than a few days CNS stimulation (such as restlessness, irritability, anxiety and insomnia) occurs with oral sympathomimetics

66

Nasal Decongestants (Cont’d)
 Adverse effects (Cont’d):




Sympathomimetics can cause vasoconstriction by stimulating α-1 adrenergic receptors. More common with oral agents Sympathomimetics cause CNS stimulation, and can produce effects similar to amphetamine. Hence, these drugs are subject to abuse
67

Nasal Decongestants (Cont’d)
 Nursing alerts:




Overuse of topical nasal decongestants can cause rebound congestion, meaning that the congestion can be worse with the use of drug. To minimise this, drug therapy should be discontinued gradually. The use of topical agents is limited to no more than 3 to 5 days

68

Nasal Decongestants (Cont’d)
 Nursing alerts (Cont’d):




The patient’s blood pressure and pulse should be assessed before a decongestant is administered Inform the patient that nasal burning and stinging may occur with topical decongestants

69

Intranasal Corticosteroids
 Intranasal Corticosteroids




Most effective for treatment of seasonal and perennial rhinitis Have inflammatory actions and can prevent or suppress all major symptoms of allergic rhinitis including congestion, rhinorrhea, sneezing, nasal itching and erythema

70

Intranasal Corticosteroids (Cont’d)
Drug Formulation Adult Dosage Child

Beclomethasone Dipropionate

Nasal Spray 50 mcg / dose

1 spray in each nostril four times daily Max. 10 sprays / day
2 applications into each nostril twice to four times daily Max. 400 mcg daily

4-6 sprays / day

Nasal Spray 50 mcg dose (Aqueous)

Same as adult (>6 yrs) Not recommended in children <6yrs

71

Intranasal Corticosteroids (Cont’d)
Drug (Cont’d) Formulation Dosage

Adult

Child

Budesonide

Nasal Spray 50 mcg / dose (Aqueous)

1-2 sprays into each nostril twice daily; after 2-3days: 1 spray into each nostril twice daily
400 mcg in the morning given as 2 applications into each nostril; then reduce to the smallest amount necessary

Not recommended for age 12 yrs or below

Turbuhaler 100mcg / dose

-

72

Intranasal Corticosteroids (Cont’d)
Drug (Cont’d) Formulation Dosage Adult Fluticasone Nasal Spray 50 mcg / dose (Aqueous) 2 sprays into each nostril in the morning Max: 8 sprays/day Child 1 spray into each nostril in the morning (4-11yrs) Max: 4 sprays/day 1 spray in each nostril once daily (3-11yrs)

Mometasone

Nasal Spray 50 mcg / dose

2 sprays in each nostril once daily; 1spray in each nostril as maintenance Max: 8 sprays/day

73

Intranasal Corticosteroids (Cont’d)
 Adverse effects:
 

Mild Most common effects are drying of nasal mucosa & sensations of burning or itching

74

Chronic Obstructive Pulmonary Disease (COPD)
 Umbrella term for various conditions



 


characterized by limitation of airflow that is not fully reversible Chronic airflow limitation caused by a mixture of small airway disease and parenchymal destruction Airflow limitation is often progressive Associated with an abnormal inflammatory response of lungs to noxious substances PREVENTABLE and TREATABLE disease
75

Relationship between COPD and emphysema/chronic bronchitis
 Emphysema



Destruction of the gas exchanging surfaces of the lung (alveoli) Pathological term that describes only one of several structural abnormalities present in patients with COPD
Presence of cough and sputum production for at least 3 months in each of two consecutive years Remains a clinically and epidemiologically useful term, but does not reflect the major impact of airflow limitation on morbidity and mortality in COPD patients

 Chronic bronchitis
 

 The emphasis on these conditions are not included in the

definition of COPD in current relevant clinical guidelines
76

Mechanisms of COPD



Ref: Global Initiative for Chronic Obstructive Lung Disease (GOLD), National Heart, Lung, and Blood Institute (U.S.) - Federal Government Agency [U.S.] World Health Organization - International Agency. 2001 (revised 2006).

77

Risk factors
 Genes  Exposure to particles



 

Tobacco smoke Occupational dusts, organic and inorganic Indoor air pollution from heating and cooking with biomass in poorly vented dwellings Outdoor air pollution

      

Lung Growth and Development Oxidative stress Gender (appears to be related to cigarette use?) Respiratory infections Socioeconomic status Nutrition Comorbidities (e.g. asthma)

78

GOLD report COPD Staging System
Stage / Severity Stage I: Mild Postbronchodilator FEV1/ FVC and FEV1 pred. FEV1/FVC < 0.70 FEV1 ≥ 80% predicted Characteristics chronic cough and sputum production may be present, but not always

Stage II: Moderate
Stage III: Severe

FEV1/FVC < 0.70 50% FEV1 < 80% predicted
FEV1/FVC < 0.70 30% FEV1 < 50% predicted

shortness of breath typically developing on exertion and cough and sputum production sometimes also present
greater shortness of breath, reduced exercise capacity, fatigue, repeated exacerbations that almost always have an impact on patients’ quality of life quality of life is very appreciably impaired and exacerbations may be life threatening

Stage IV: Very severe

FEV1/FVC < 0.70 FEV1 < 30% predicted or FEV1 < 50% predicted plus chronic respiratory failure

FEV1: forced expiratory volume in one second FVC: forced vital capacity Respiratory failure: arterial partial pressure of oxygen (PaO2) less than 8.0 kPa (60 mm Hg) with or without arterial partial pressure of CO2 (PaCO2) greater than 6.7 kPa (50 mm Hg) while breathing air at sea level

79

Asthma and COPD
 Underlying cause is different  Asthma: eosinophilic inflammation  COPD: neutrophilic inflammation

 COPD can coexist with asthma  While asthma can usually be

distinguished from COPD, in some individuals with chronic respiratory symptoms and fixed airflow limitation it remains difficult to differentiate the two diseases
80

Differences in causes of COPD and asthma

81

Clinical features in COPD and asthma

82

Pharmacotherapy
 None of the current available medications can

alter the natural course of COPD or modify the rate of decline in lung function  Aims (as per GOLD report)


 
  



Relieve symptoms Prevent disease progression Improve exercise tolerance Improve health status Prevent and treat complications Prevent and treat exacerbations Reduce mortality
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Bronchodilators
 Bronchodilator medications are central to

symptom management in COPD  Inhaled therapy is preferred  The choice between beta agonist, anticholinergic, theophylline, or combination therapy depends on availability and individual response in terms of symptom relief and side effects
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Bronchodilators (Cont’d)
 Bronchodilators are prescribed on an as-

needed or on a regular basis to prevent or reduce symptoms  Long-acting inhaled bronchodilators are more effective and convenient  Combining bronchodilators may improve efficacy and decrease the risk of side effects compared to increasing the dose of a single bronchodilator
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Corticosteroids
 Effects of oral and inhaled

corticosteroids in COPD are much less dramatic than in asthma, and their role in the management of stable COPD is limited to specific indications

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Oral corticosteroids
 Use of a short course (two weeks) of oral

corticosteroids to identify COPD patients who might benefit from long-term treatment with oral or inhaled corticosteroids is recommended  Due to lack of evidence of benefit, and the issue of side effects, long-term treatment with oral corticosteroids is not recommended in COPD
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Inhaled corticosteroids
 Regular treatment is appropriate for

symptomatic Stage III and Stage IV CPOD and repeated exacerbations (for example, 3 in the last 3 years)  Treatment has been shown to reduce the frequency of exacerbations and thus improve health status  More effective when combined with a long-acting beta agonist
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