pharmacology 2 respiratory

What is cough?

A protective reflex action that clears the throat of mucus or foreign irritants.

What is the physiological role of cough?

Protection of the respiratory tract by clearing secretions and irritants.

Why is cough considered a common symptom?

It occurs in many respiratory diseases.

How is cough classified according to duration?

Acute, subacute, and chronic.

How long does acute cough last?

Less than 3 weeks.

How long does subacute cough last?

Between 3 and 8 weeks.

How long does chronic cough last?

More than 8 weeks.

How is cough classified according to type?

Productive or nonproductive.

What is productive cough?

Cough associated with sputum production.

What is nonproductive cough?

Dry cough without sputum.

What infectious causes can lead to cough?

Viral infections, bacterial infections, and tuberculosis.

Give examples of viral causes of cough.

Common cold.

Give examples of bacterial causes of cough.

Pneumonia.

What non-infectious diseases can cause cough?

Asthma, COPD, and GERD.

What environmental factors can cause cough?

Exposure to allergens, smoke, and pollutants.

Which drug class commonly causes cough as a side effect?

ACE inhibitors.

What nerve is involved in the afferent limb of the cough reflex?

Vagus nerve.

Where is the cough center located?

In the brainstem.

What structures form the efferent limb of the cough reflex?

Nerves supplying respiratory muscles.

What are the two main principles of cough management?

Treat the underlying cause and relieve symptoms.

What are the steps in history taking for cough assessment?

Duration, pattern, associated symptoms, and exposure to irritants.

What associated symptoms are important in cough history?

Fever, wheezing, and chest pain.

What does physical examination of cough include?

Auscultation of lungs and examination of nasal passages, throat, and chest.

What diagnostic tests may be used in cough evaluation?

Chest X-ray, spirometry, blood tests, sputum analysis, and bronchoscopy.

What are the main non-specific treatments of cough?

Antitussives, mucolytics, and expectorants.

For which type of cough are antitussives mainly used?

Dry cough.

How do peripheral antitussives work?

By decreasing afferent impulses.

Give examples of peripheral antitussives.

Steam inhalation, demulcents like liquorice and honey.

Which drug has both peripheral and central antitussive action?

Benzonatate.

How do central antitussives act?

They inhibit the cough center.

Give examples of opioid central antitussives.

Codeine and hydrocodone.

From what are opioid antitussives derived?

Morphine.

What is a major risk of long-term opioid antitussive use?

Drug dependence.

Which opioid isomer is used as a central antitussive?

Dextromethorphan.

Where is dextromethorphan commonly used?

OTC cold and cough preparations.

What is the main mechanism of action of dextromethorphan?

Suppression of the cough center in the medulla oblongata.

What additional pharmacologic action does dextromethorphan have?

Non-selective serotonin reuptake inhibition.

What are common side effects of dextromethorphan at therapeutic doses?

Dizziness, drowsiness, and gastrointestinal discomfort.

What symptoms indicate dextromethorphan overdose?

Confusion, hyperexcitability, hallucinations, ataxia, lethargy, respiratory depression, and coma.

How is dextromethorphan overdose managed?

Supportive care, airway protection, and sometimes activated charcoal or naloxone.

Which drug interactions increase the risk of serotonin syndrome with dextromethorphan?

SSRIs and MAOIs.

What is serotonin syndrome?

A potentially life-threatening condition due to excess serotonergic activity.

Which enzyme inhibitors increase dextromethorphan toxicity?

CYP2D6 inhibitors like fluoxetine and paroxetine.

What are the advantages of dextromethorphan?

Safe in pregnancy, no tolerance, no addiction, minimal sedation.

What are mucolytics?

Drugs that break down mucus structure and reduce viscosity.

Why are mucolytics important in respiratory diseases?

They facilitate mucus clearance.

In which chronic conditions are mucolytics especially useful?

COPD, bronchiectasis, and cystic fibrosis.

In which acute conditions are mucolytics used?

Pneumonia.

What are the common side effects of mucolytics?

GIT upset, bronchospasm, and hypersensitivity.

What are expectorants?

Drugs that loosen and thin mucus to aid its removal.

When are expectorants commonly indicated?

Conditions with excessive or thick mucus.

Which respiratory conditions commonly require expectorants?

Bronchitis, common cold, pneumonia, and respiratory infections.

Name an inorganic expectorant.

Potassium iodide.

Name a commonly used OTC expectorant.

Guaifenesin.

How does guaifenesin act?

Increases bronchial fluid secretion by an unclear mechanism.

Name other traditional expectorants.

Ammonium chloride, tincture ipecacuanha, and herbal remedies.

Why should antitussives be avoided in productive cough?

Because cough helps expel sputum.

What is the best treatment for productive cough with thick sputum?

Expectorants or mucolytics.

What is the likely cause of dry cough in a patient taking enalapril?

ACE inhibitor-induced cough.

What is the best management of ACE inhibitor-induced cough?

Stop the ACE inhibitor and switch to another class.