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RESPIRATORY DISORDERS

Respiratory Tract Drugs

To treat acute & minor

conditions

1. Nasal congestion

2. Cough

3. Seasonal allergies

To treat chronic &

serious conditions

1. Bronchial Asthma

2. Chronic bronchitis

3. Cystic fibrosis

4. Emphysema

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Drugs used to treat respiratory tract irritation &

control secretion

These drugs are used to treat symptoms of cough &

irritation that result from:

– Common cold

– Seasonal allergies

– Upper respiratory tract infections.

This group includes:

1. Antitussives

2. Decongestant

3. Antihistamines

4. Mucolytics & Expectorants

1-Antitussives

• The drugs used to suppress cough associated with common cold &

minor throat irritation.

• They are usually prescribed only for short term use in relieving

symptomatic coughing.

1. Codeine

2. Hydrocodone

3. Diphenhydramine

Common side effects are: Sedation, Dizziness, GIT upset

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• Congestion & mucosal discharge (runny nose) are features of many

respiratory conditions like:

1. Allergies

2. Common cold

3. Respiratory Tract Infections

• Most of the used drugs are alpha-1 agonists to stimulate the alpha-1

receptors in the blood vessels of the nasal mucosa.

• It cause vasoconstriction & effectively drying up the mucosal

vasculature & decreasing local congestion in the nasal passages.

• Can be given systemically or locally.

Common side effects are: Headache, Dizziness, Nervousness, Nausea

and CVS problems

2-Decongestants

3-Anti-histamines

• Histamine is an endogenous chemical that regulate many

physiologic functions:

• Gastric secretion

• CNS modulation

• Hypersensitivity (allergic) reactions.

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Type of

receptor Location Function

H1 • Smooth muscle

• Endothelium

• CNS

• Vasodilation

• Bronchoconstriction

• Redness, pain and itching

• Motion sickness

• Sleep regulation.

H2 • Parietal cells in

stomach

• Stimulate gastric acid secretion

H3 • CNS •Decrease neurotransmitter release:

histamine, acetylcholine,

norepinephrine, serotonin

H4 • Basophils

• Bone marrow

• Plays a role in chemotaxis.

3-Anti-histamines

Histamine receptors

• They specifically block H1-receptors.

• These drugs are used in rhinitis, sinusitis & conjunctivitis to

decrease:

o Nasal congestion

o Mucosal irritation

o Discharge

o Cough

o Sneezing

3-Anti-histamines

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Sedating antihistamines

(e.g. diphenhydramine)

Selected adverse effects:

Dry mouth

Hypotension

CNS depression

Antimuscarinic

3-Anti-histamines

Less sedating antihistamines

(e.g. Loratadine)

Little access to brainNo antimuscarinic actions

Selected adverse effects Dry mouth, drowsiness, fatigue, headache

3-Anti-histamines

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4-Mucolytics & Expectorants

Mucolytics are drugs that decrease viscosity of respiratory

secretions.

Expectorants are drugs which facilitate production &

ejection of mucous.

• These drugs are used to prevent the accumulation of

thick & viscous secretions that may block the respiratory

passages & lead to pulmonary problems.

Drugs used to treat chronic

&

serious conditions

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• Airway obstruction is a major problem in respiratory

disorders such as

o Bronchial asthma

o Cystic fibrosis

o Chronic bronchitis

o Emphysema

• The goal of drug therapy of these conditions is to prevent

or reverse the bronchial constriction & obstruction of the

airways by the use of

o Bronchodilators

o Anti-inflammatory agents.

COPD

Bronchodilators

• This group of drugs used to treat bronchospasm. It includes:

1. Beta adrenergic agonists

2. Theophylline

3. Anticholinergics

4. Sodium cromoglycate

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1- Beta Adrenergic Agonist Drugs

• They bind to Beta-2 receptors, stimulating them & result in

relaxation of the respiratory smooth muscles and produce

bronchodilation.

• Also can be used to prevent bronchospasm (Prophylactic) .

Adverse Effects:

o Bronchial irritation (inhalers)

o Cardiac irregularities (non selectivity)

o Stimulation of CNS adrenergic receptors.

2- Theophylline

It has the following effects:

o Bronchodilation

o Increase mucociliary transport

o Decrease pulmonary artery pressure

o Increase respiratory muscles strength

o Limit the release of inflammatory mediators

Adverse Effects:

o Nausea, vomiting, confusion, irritability, cardiac

arrhythmias, seizure.

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3- Anticholinergic Drugs

• Atropine & Ipratropium

• Anticholinergic drugs can inhibit bronchoconstriction in

cases of bronchial asthma & COPD.

Side effects

• Dry mouth

• Tachycardia

• Constipation

• Urine retention

• Blurring of vision

4-Sodium Cromoglycate

• This drug is commonly used to prevent bronchospasm (prophylaxis)

initiated by exercise.

• Stabilizes the pulmonary mast cells & inhibits the release of

inflammatory mediators (histamine & leukotrienes).

• It can be given by:

o Inhalation

o Nebulizer

o Nasal spray

Side effects:

• Irritation to the upper respiratory passages when given by inhalation.

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Anti-inflammatory Drugs

• Inflammation is an important factor for the

bronchospasm in case of bronchial asthma & COPD.

• Corticosteroids have very potent anti-inflammatory

effects so they can control inflammation mediated

bronchoconstriction.

• NSAIDs should not be used (Why?)

Bronchial Asthma

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• Asthma is a chronic inflammatory disorder of the

airway caused mostly by an immunologic reaction

• Is a disease of the respiratory tract in which there is

widespread airways obstruction.

• Three factors contribute to the narrowing of airways.

1. Mucosal cells swelling/inflammation

(responds well to steroids)

2. Mucous formation

3. Bronchial smooth muscle contraction

(responds to Beta-2 agonists)

BronchialAsthma

Clinical Features:

1.Intermittent wheeze

2.Dyspnoae

3.Cough

Precipitating Factors:

o Emotion

o Exercise

o Infection

o Allergens

o Drugs

o Cold air

BronchialAsthma

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Management of Bronchial Asthma

• Bronchodilators

• Theophylline

• Corticosteroids

Non-pharmacologic Management

1. Identification of the initiating factors

2. Aerobic exercise (swimming) is excellent to improve

cardiorespiratory function in patient with asthma without

causing bronchospasm.

BronchialAsthma

BronchialAsthma

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Chronic Obstructive Pulmonary Disease

(COPD)

Chronic Obstructive Pulmonary Disease

(COPD)

• Is persistent obstruction of the airways.

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Chronic Bronchitis

• Long-standing inflammation of the bronchial tree

• Characterized by production of sputum on most days

for 3 months of 2 successive years.

• May cause obstruction and narrowing of the airway

lumen with excess mucous.

COPD

Emphysema

• A pathological condition in which there is dilatation of

the air spaces by destruction of the alveolar walls.

• Obstruction results from the decrease of the lungs’

elasticity, which normally holds the airways open in

expiration.

COPD

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1. Smoking

2. Alpha-1 anti-trypsin deficiency

COPD

Smoking

• Cigarette smoking is the most important cause of COPD, although only about 15% of smokers developthe disease.

• Lung function improves only a little if people stop

smoking.

• With aging, susceptible cigarette smokers lose

lung function more rapidly than nonsmokers.

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Alpha1-Antitrypsin (A1AT)

• A1AT is an enzyme produced by the liver which

inhibits the action of other enzymes called proteases.

• Proteases break down proteins as part of normal

tissue repair.

• A1AT protects the lungs from the damaging effects of

proteases.

• Genetic deficiency of A1AT or due to smoking causes

Emphysema.

1. Cough

2. Excessive Sputum

3. Dyspnoea

4. Wheezing

5. Hyperinflation

6. Cyanosis

7. Loss of weight

Features of COPD

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The aim of treatment is to maintain the airway open & prevent

airflow restriction.

1. Bronchodilators (β-2 agonist , anticholinergic,theophylline)

2. Corticosteroids

3. Mucolytics & Expectorants

4. Chest physiotherapy

Treatment of COPD

Cystic Fibrosis

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Cystic Fibrosis

• It is a hereditary disease characterized by abnormal transport of

chloride and sodium across an epithelium, leading to thick,

viscous secretions

• Mucous plugging of the bronchioles may result in:

1. Pneumonia

2. Bronchitis

3. Pulmonary fibrosis

The aim of treatment is to maintain the airway patent as much

as possible.

1. Bronchodilators

2. Mucolytics & Expectorants

3. Corticosteroids

4. Antibiotics to treat infections

Treatment of Cystic Fibrosis

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