Transcript Drugs Acting on the Respiratory System

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


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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:


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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:
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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
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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
Salbutamol
Terbutaline
Formulation
Dosage
Adult
Child
Oral tablet (C.R)
8 mg twice daily
4 mg twice daily
Inhaler (MDI), 100mcg/dose
100-200mcg up to three to
four times daily
Same as adult
Syrup, 2mg/5ml
4 mg three to four times
daily
1-2 mg three to four times
daily (≥2 yr)
Oral tablet (S.R)
5-7.5 mg two times daily
-
Inhaler 500mg / dose
( Turbuhaler)
500 mcg up to four times
daily
-
Inhaler 250mg / dose (MDI)
250-500mcg up to 3-4 times
daily
Same as adult
13
Bronchodilators (Cont’d)
Long-acting β-2 agonists
Drug
Formoterol
Formulation
Inhaler 4.5mcg / dose
(Turbuhaer)
Dosage
Adult
Child
4.5-9 mcg once or twice
daily
Same as adult
50-100 mcg twice daily
Same as adult
Inhaler 9mcg / dose
(Turbuhaer)
Salmeterol
Inhaler 25mcg / dose
(MDI)
50 mcg / dose (Accuhaler) 50 mcg twice
Same as adult
14
Bronchodilators (Cont’d)
 Adverse effects
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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
17
Bronchodilators (Cont’d)
 Antimuscarinic bronchodilators
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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
18
Bronchodilators (Cont’d)
Drug
Formulation
Dosage
Adult
Child
Ipratropium
Inhaler 20 mcg / dose
(MDI)
20-80 mcg three to four
times a day
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:
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Dry mouth
Nausea
Constipation
Headache
20
Bronchodilators (Cont’d)
 Xanthine Derivatives
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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
Theophylline
Aminophylline
Formulation
Dosage
Adult
Child
Tablet 200 / 300 mg
(S.R.)
200 – 300 mg twice daily
10 mg / kg ((≥2yrs) twice
daily
Capsule 50 / 100 mg
(Slow release)
7-12 mg/ kg / day in two divided
doses
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)
Injection 25 mg / ml
10 ml
500 mcg / kg / hr IV infusion,
adjust when necessary
1 mg / kg /hr (6 months – 9
years)
800 mcg / kg /hr (10 – 16 yrs)
IV infusion, adjust when
necessary
22
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
25
Corticosteroids
 Used for prophylaxis of chronic asthma
 Suppressing inflammation
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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
26
Corticosteroids (Cont’d)
Drug
Beclomethasone
Formulation
Dosage
Adult
Child
Inhaler 50 mcg / dose
(MDI)
200 mcg twice daily /
100mcg three to fours
times daily
Up to 800 mcg daily
50 – 100 mcg two to four
times daily
Inhaler 250 mcg / dose
(MDI)
500 mcg twice daily / 250
mcg four times daily
Not recommended
27
Corticosteroids (Cont’d)
Drug (Cont’d)
Budesonide
Formulation
Inhaler 50 mcg / dose
(MDI)
Dosage
Adult
Child
200 mcg twice daily
Up to 1.6 mg daily
50 – 400 mcg twice
daily
Up to 800 mcg daily
200-800 mcg once daily
in evening
Up to 1.6 mg daily in
two divided doses
200-800 mcg daily in
two divided doses /
200-400 mcg once
daily in evening
(<12 yrs)
Inhaler 200mcg / dose
(MDI)
Inhaler 100 mcg / dose
(Turbuhaler)
Inhaler 200 mcg / dose
(Turbuhaler)
Inhaler 400 mcg / dose
(Turbuhaler)
28
Corticosteroids (Cont’d)
Drug (Cont’d)
Fluticasone
Formulation
Inhaler 25mcg / dose (MDI)
Inhaler 50 mcg / dose (MDI)
Dosage
Adult
Child
100 – 1000 mcg
twice daily
50-100 mcg twice daily
(4-16 yrs)
Inhaler 125 mcg / dose (MDI)
Inhaler 250 mcg / dose (MDI)
Inhaler 50 mcg / dose (Accuhaler)
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
29
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
 Symbicort
(160mcg Budesonide+4.5mcg
Formoterol / dose, Turbuhaler)
 Seretide (Salmeterol+Fluticasone: MDi in Lite,
Medium, Forte preparation & Accuhaler)
32
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
Cromoglycate Na
Nedocromil
Sodium
Formulation
Dosage
Adult
Child
Inhaler (1 mg
& 5mg/dose)
10 mg four times daily, may be
increased to six to eight times
daily
Same as adult
Nebuliser
solution 10 mg
/ ml 2 ml
20 mg four times daily, may be
increased six times daily
Same as adult
Inhaler 2 mg /
dose (MDI)
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
36
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:

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GI disturbances
Hypersensitivity reactions
Restlessness & headache
Upper respiratory tract infection
Manufacturer advises to avoid these drugs
in pregnancy & breast-feeding unless
essential
39
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)
 Step
3: Add long-acting inhaled beta2 agonist;
dose of inhaled corticosteroid may also be increased
 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
Dosage
Adult
Child
Chorpheniramine
(4 mg tablet,
2mg/ml Elixir &
expectorant)
4 mg q4-6hr, max: 24 mg
daily
1-2yrs: 1 mg twice daily
2-12yrs: 1- 2 mg q4-6h, Max:12 mg daily
Hydroxyzine (25
mg tablet)
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
Diphendramine (10
mg/5ml Elixir)
25-50 mg q4-6h
6.25-25 mg q4-8 hr ( >1 yr)
48
Antihistamines (Cont’d)
Drug (Cont’d)
Dosage
Adult
Child
Promethazine (10 &
25 mg tablets,
5mg/5ml Elixir)
25 mg at night; 25 mg twice daily
if needed
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
Child
Acrivastine
(Semprex)
8 mg three times daily
Not recommended
Cetirizine
(Zyrtec)
10 mg daily
5 mg daily / 2.5 mg twice daily (2-6 yrs)
Desloratadine
(Aerius)
5 mg daily
1.25 mg daily (2-5 yrs)
2.5 mg daily (6-11yrs)
Fexofenadine
(Telfast)
120-180 mg daily
Not recommended
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
10-30 mg q4-8h
Diphenhydramine 10 mg/ 5ml
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
 100
mg two to four times daily
 200 mg two to three times daily
 600 mg once daily

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
 Oral administration:

Response are delayed, moderate &
prolonged
64
Nasal Decongestants (Cont’d)
Drug
Formulation
Dosage
Adult
Child
Nasal Drops 0.025% 20 ml
-
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%)
Oxymetazoline
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
Beclomethasone
Dipropionate
Formulation
Dosage
Adult
Child
Nasal Spray 50 mcg /
dose
1 spray in each nostril
four times daily
Max. 10 sprays / day
4-6 sprays / day
Nasal Spray 50 mcg
dose (Aqueous)
2 applications into
each nostril twice to
four times daily
Max. 400 mcg daily
Same as adult (>6 yrs)
Not recommended in
children <6yrs
71
Intranasal Corticosteroids (Cont’d)
Drug (Cont’d)
Budesonide
Formulation
Dosage
Adult
Child
Nasal Spray 50 mcg /
dose (Aqueous)
1-2 sprays into each
nostril twice daily; after
2-3days: 1 spray into
each nostril twice daily
Not recommended for
age 12 yrs or below
Turbuhaler 100mcg /
dose
400 mcg in the morning
given as 2 applications
into each nostril; then
reduce to the smallest
amount necessary
-
72
Intranasal Corticosteroids (Cont’d)
Drug (Cont’d)
Formulation
Dosage
Adult
Child
Fluticasone
Nasal Spray 50 mcg
/ dose (Aqueous)
2 sprays into each
nostril in the morning
Max: 8 sprays/day
1 spray into each
nostril in the morning
(4-11yrs)
Max: 4 sprays/day
Mometasone
Nasal Spray 50 mcg
/ dose
2 sprays in each
nostril once daily;
1spray in each nostril
as maintenance
Max: 8 sprays/day
1 spray in each
nostril once daily
(3-11yrs)
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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
 Chronic bronchitis


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
 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
Postbronchodilator
FEV1/ FVC and FEV1 pred.
Characteristics
Stage I:
Mild
FEV1/FVC < 0.70
FEV1 ≥ 80% predicted
chronic cough and sputum production may be
present, but not always
Stage II:
Moderate
FEV1/FVC < 0.70
50%  FEV1 < 80% predicted
shortness of breath typically developing on
exertion and cough and sputum production
sometimes also present
Stage III:
Severe
FEV1/FVC < 0.70
30%  FEV1 < 50% predicted
greater shortness of breath, reduced exercise
capacity, fatigue, repeated exacerbations that
almost always have an impact on patients’ quality
of life
Stage IV:
Very
severe
FEV1/FVC < 0.70
FEV1 < 30% predicted or FEV1 <
50% predicted plus chronic
respiratory failure
quality of life is very appreciably impaired and
exacerbations may be life threatening
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
83
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
84
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
85
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
86
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
87
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
88
89
90