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Drugs Used in Cough

Introduction

Cough is a protective reflex that helps clear the respiratory tract of irritants, secretions, and foreign particles. While it serves an essential physiological role, excessive or persistent cough can become distressing and may indicate underlying pathology. Pharmacological management of cough depends on its type (dry or productive), underlying cause, and patient-specific factors.

Drugs used in cough are broadly classified into antitussives (cough suppressants) and expectorants/mucolytics (cough promoters), along with adjunctive agents that target associated symptoms such as inflammation, infection, or bronchospasm.

Classification of Drugs Used in Cough

1. Antitussives (Cough Suppressants)

These drugs suppress the cough reflex and are mainly used in dry (non-productive) cough.

A. Centrally Acting Antitussives

These act on the cough center in the medulla.

Opioid Antitussives

Codeine
Pholcodine

Mechanism:

Suppress cough center in the brain
Reduce frequency and intensity of cough

Advantages:

Effective in severe dry cough

Disadvantages:

Sedation
Respiratory depression (especially in children)
Risk of dependence

Non-Opioid Centrally Acting Drugs

Dextromethorphan
Noscapine

Mechanism:

Act on cough center without opioid effects

Advantages:

Less sedation
No addiction potential

B. Peripherally Acting Antitussives

These reduce cough by acting on sensory receptors in respiratory tract.

Levodropropizine
Benzonatate

Mechanism:

Decrease sensitivity of cough receptors

2. Expectorants and Mucolytics

These drugs are used in productive (wet) cough to facilitate removal of mucus.

A. Expectorants

They increase bronchial secretions, making mucus easier to expel.

Guaifenesin
Ammonium chloride
Potassium iodide

Mechanism:

Increase hydration of mucus
Reduce viscosity

B. Mucolytics

These drugs break down mucus structure.

Bromhexine
Ambroxol
Acetylcysteine
Carbocisteine

Mechanism:

Break disulfide bonds in mucus
Reduce thickness of sputum

3. Bronchodilators in Cough

Used when cough is associated with bronchospasm (e.g., asthma, COPD).

Salbutamol
Terbutaline
Theophylline

Mechanism:

Relax bronchial smooth muscles
Improve airflow

4. Antihistamines in Cough

Used mainly in allergic cough or postnasal drip.

Diphenhydramine
Chlorpheniramine
Loratadine

Mechanism:

Block histamine receptors
Reduce allergy-induced cough

5. Corticosteroids

Used in inflammatory conditions like asthma or severe bronchitis.

Prednisolone
Budesonide

Mechanism:

Reduce airway inflammation
Decrease hypersensitivity

6. Antibiotics (When Infection is Present)

Not routinely used in cough unless bacterial infection is confirmed.

Examples:

Amoxicillin
Azithromycin

7. Demulcents

These soothe irritated throat mucosa.

Examples:

Honey
Lozenges
Syrups

Mechanism:

Form protective coating over mucosa
Reduce irritation-induced cough

8. Combination Preparations

Many cough syrups combine multiple agents:

Antitussive + Antihistamine
Expectorant + Bronchodilator
Mucolytic + Decongestant

Example combinations:

Dextromethorphan + Chlorpheniramine
Guaifenesin + Salbutamol

Factors Affecting Drug Selection

Type of cough (dry vs productive)
Age of patient (children vs adults)
Underlying disease (asthma, infection, allergy)
Duration of cough (acute vs chronic)
Presence of comorbidities

Special Considerations in Children

Avoid codeine due to risk of respiratory depression
Prefer safer drugs like dextromethorphan or honey (>1 year age)
Use correct dosing based on weight

Adverse Effects of Cough Drugs

Sedation (antihistamines, opioids)
Nausea and vomiting
Dizziness
Constipation (opioids)
Allergic reactions

Non-Pharmacological Measures

Adequate hydration
Steam inhalation
Avoid irritants (smoke, dust)
Humidified air

Pathophysiological Basis of Drug Use

Cough reflex involves:

Receptors in respiratory tract
Afferent pathways (vagus nerve)
Central cough center
Efferent pathways

Drugs act at different levels:

Central suppression (antitussives)
Peripheral inhibition (local agents)
Mucus clearance (expectorants/mucolytics)

Emerging Therapies

Recent research is focusing on:

P2X3 receptor antagonists
Novel neuromodulators for chronic cough
Targeted anti-inflammatory therapies

Detailed Pharmacology of Antitussives

Centrally Acting Opioid Antitussives

Codeine

Pharmacodynamics:

Acts on μ-opioid receptors in the medullary cough center
Elevates the threshold for cough reflex

Pharmacokinetics:

Well absorbed orally
Metabolized in liver (partly converted to morphine via CYP2D6)
Duration: 4–6 hours

Clinical Uses:

Severe dry cough
Nocturnal cough disturbing sleep

Adverse Effects:

Sedation
Constipation
Respiratory depression
Dependence potential

Contraindications:

Children <12 years
Respiratory disorders (e.g., asthma exacerbation)

Pholcodine

Key Features:

Similar to codeine but less addictive
Longer duration of action

Adverse Effects:

Mild sedation
Rare hypersensitivity reactions

Non-Opioid Central Antitussives

Dextromethorphan

Mechanism:

Acts on NMDA receptors and sigma receptors in CNS
Suppresses cough center without analgesic or addictive effects

Pharmacokinetics:

Rapid oral absorption
Metabolized in liver

Advantages:

Widely used and safe
Minimal respiratory depression

Adverse Effects:

Drowsiness (mild)
High doses → hallucinations (abuse potential)

Noscapine

Mechanism:

Acts centrally without opioid receptor activation

Advantages:

No respiratory depression
No addiction

Adverse Effects:

Mild sedation
Rare hypotension

Peripheral Antitussives in Detail

Benzonatate

Mechanism:

Anesthetizes stretch receptors in respiratory passages

Clinical Use:

Irritative cough

Important Note:

Capsule must not be chewed (causes oral numbness and choking risk)

Levodropropizine

Mechanism:

Inhibits sensory neuropeptide release

Advantages:

Less sedation
Preferred in children in some settings

Expectorants: Advanced Concepts

Guaifenesin

Mechanism:

Stimulates gastric mucosa → reflex increase in respiratory secretions

Effect:

Converts dry cough into productive cough

Pharmacokinetics:

Short half-life → requires frequent dosing

Ammonium chloride

Mechanism:

Mild irritant → increases bronchial secretions

Additional Effect:

Systemic acidifying agent

Potassium iodide

Mechanism:

Direct stimulation of secretory glands

Adverse Effects:

Iodism (metallic taste, salivation, rash)

Mucolytics: In-Depth

Acetylcysteine

Mechanism:

Breaks disulfide bonds in mucoproteins
Also acts as antioxidant

Additional Use:

Antidote in paracetamol poisoning

Administration:

Nebulized or oral

Bromhexine

Ambroxol

Mechanism:

Enhance lysosomal enzyme activity
Improve mucociliary clearance

Additional Benefit:

Ambroxol has mild local anesthetic effect

Carbocisteine

Mechanism:

Regulates mucus composition
Reduces viscosity without excessive thinning

Bronchodilators and Their Role in Cough

Salbutamol

Terbutaline

Mechanism:

Stimulate β2 receptors → bronchodilation

Indications:

Asthma-related cough
Wheezing with cough

Adverse Effects:

Tremors
Tachycardia

Theophylline

Mechanism:

Phosphodiesterase inhibition → ↑ cAMP

Additional Effects:

Mild anti-inflammatory action

Limitations:

Narrow therapeutic index

Antihistamines in Cough Management

Diphenhydramine

Chlorpheniramine

Mechanism:

H1 receptor blockade
Reduce allergic inflammation

Additional Benefit:

Sedative → useful in nighttime cough

Loratadine

Advantages:

Non-sedating
Longer duration

Corticosteroids: Expanded Discussion

Prednisolone

Budesonide

Mechanism:

Suppress inflammatory cytokines
Reduce airway edema

Indications:

Chronic cough due to asthma
Severe bronchitis

Antibiotics in Cough

Amoxicillin

Azithromycin

Indications:

Bacterial bronchitis
Pneumonia
Pertussis

Important Principle:

Avoid unnecessary use in viral cough

Fixed Dose Combinations (FDCs)

Common combinations include:

Antitussive + Antihistamine
- Dextromethorphan + Chlorpheniramine
Expectorant + Bronchodilator
- Guaifenesin + Salbutamol
Mucolytic + Antibiotic (rare but used in severe infections)

Clinical Approach to Cough Treatment

Dry Cough

Preferred: Antitussives
Example: Dextromethorphan

Productive Cough

Preferred: Expectorants/Mucolytics
Avoid strong cough suppressants

Allergic Cough

Antihistamines ± corticosteroids

Asthmatic Cough

Bronchodilators + inhaled steroids

Chronic Cough: Pharmacological Approach

Defined as cough >8 weeks.

Common causes:

Asthma
GERD
Postnasal drip

Drugs used:

Bronchodilators
Proton pump inhibitors
Antihistamines

Special Populations

Elderly

Avoid sedative drugs
Increased risk of respiratory depression

Pregnancy

Prefer non-drug therapy
Use drugs only if necessary

Pediatric Considerations

Avoid codeine
Use safe alternatives

Drug Interactions

Dextromethorphan + MAO inhibitors → serotonin syndrome
Theophylline + antibiotics → toxicity
Antihistamines + alcohol → excessive sedation

Toxicity and Overdose

Opioids → respiratory depression
Theophylline → seizures, arrhythmias
Antihistamines → CNS depression

Pharmacological Pearls (Exam-Oriented)

Codeine → most effective antitussive but addictive
Dextromethorphan → safest widely used suppressant
Guaifenesin → most common expectorant
Acetylcysteine → mucolytic + antidote
Salbutamol → best for cough with bronchospasm

Dosage Regimens of Common Drugs Used in Cough

Antitussives

Dextromethorphan

Adults:

10–20 mg every 4–6 hours
Maximum: 120 mg/day

Children:

6–12 years: 5–10 mg every 4–6 hours
<6 years: generally not recommended without medical advice

Codeine

Adults:

10–20 mg every 4–6 hours

Children:

Contraindicated under 12 years

Benzonatate

Adults:

100–200 mg three times daily

Important:

Swallow whole (do not chew)

Expectorants

Guaifenesin

Adults:

200–400 mg every 4 hours

Children:

6–12 years: 100–200 mg every 4 hours

Mucolytics

Acetylcysteine

Adults:

200–600 mg/day orally in divided doses
Nebulized form also used

Ambroxol

Adults:

30 mg 2–3 times daily

Children:

Dose adjusted according to age

Clinical Case-Based Drug Selection

Case 1: Dry Nocturnal Cough

Likely cause: Viral infection or post-infectious cough
Drug of choice:
- Dextromethorphan
Alternative:
- Codeine (if severe)

Case 2: Productive Cough with Thick Sputum

Likely cause: Bronchitis
Drug of choice:
- Acetylcysteine
- Guaifenesin

Case 3: Allergic Cough with Sneezing

Likely cause: Allergic rhinitis
Drug of choice:
- Loratadine
- Chlorpheniramine

Case 4: Cough with Wheezing

Likely cause: Asthma
Drug of choice:
- Salbutamol
- Budesonide

Case 5: Cough with Fever and Purulent Sputum

Likely cause: Bacterial infection
Drug of choice:
- Amoxicillin
- Azithromycin

OSCE and Viva Points

Always differentiate dry vs productive cough before prescribing
Avoid suppressing productive cough → may worsen condition
Codeine → contraindicated in children
Dextromethorphan → safest antitussive
Hydration enhances effect of expectorants

Stepwise Management of Cough

Step 1: Identify Type

Dry → Antitussive
Productive → Expectorant/Mucolytic

Step 2: Identify Cause

Infection → Antibiotics (if bacterial)
Allergy → Antihistamines
Asthma → Bronchodilators

Step 3: Add Supportive Therapy

Steam inhalation
Fluids

Cough Reflex Pathway and Drug Targets

Receptors: Irritant receptors in airway
Afferent limb: Vagus nerve
Central processing: Medulla
Efferent limb: Respiratory muscles

Drug Targets:

Central → Dextromethorphan, Codeine
Peripheral → Benzonatate
Secretions → Guaifenesin, Acetylcysteine

Comparative Table of Key Drugs

Drug	Class	Use	Key Feature
Dextromethorphan	Antitussive	Dry cough	Safe, non-addictive
Codeine	Opioid	Severe cough	Strong but addictive
Guaifenesin	Expectorant	Productive cough	Increases secretions
Acetylcysteine	Mucolytic	Thick sputum	Breaks mucus bonds
Salbutamol	Bronchodilator	Asthma cough	Relieves bronchospasm

Advanced Concepts in Chronic Refractory Cough

Chronic cough not responding to standard therapy may involve neural hypersensitivity.

Newer Drugs Under Study:

P2X3 receptor antagonists (e.g., Gefapixant)
Neuromodulators (gabapentin in selected cases)

Role of Non-Drug Therapy in Detail

Steam Inhalation

Moistens airway
Loosens mucus

Hydration

Essential for mucolytic effectiveness

Honey

Natural demulcent
Useful in children >1 year

Red Flag Signs in Cough

Hemoptysis
Weight loss
Persistent fever
Chronic cough >8 weeks
Breathlessness

These require further evaluation before giving symptomatic treatment.

Common Mistakes in Prescribing

Using antitussives in productive cough
Overuse of antibiotics in viral infections
Ignoring underlying cause
Giving codeine to children

Integration with Respiratory Diseases

In Asthma

Bronchodilators + steroids

In COPD

Mucolytics + bronchodilators

In Tuberculosis

Antitussives avoided
Treat underlying disease

High-Yield MCQs on Drugs Used in Cough

MCQ 1

A patient presents with dry irritating cough at night. Which drug is most appropriate?
A. Guaifenesin
B. Acetylcysteine
C. Dextromethorphan
D. Salbutamol

Answer: C
Explanation: Dry cough requires suppression → antitussive drug.

MCQ 2

Which drug should be avoided in productive cough?
A. Guaifenesin
B. Ambroxol
C. Codeine
D. Acetylcysteine

Answer: C
Explanation: Suppressing productive cough leads to mucus retention.

MCQ 3

Which drug acts by breaking disulfide bonds in mucus?
A. Guaifenesin
B. Acetylcysteine
C. Dextromethorphan
D. Loratadine

Answer: B

MCQ 4

Which drug is contraindicated in children under 12 years?
A. Dextromethorphan
B. Codeine
C. Ambroxol
D. Guaifenesin

Answer: B

MCQ 5

A patient with cough and wheezing should receive:
A. Chlorpheniramine
B. Salbutamol
C. Codeine
D. Amoxicillin

Answer: B

Clinical Case Scenarios (Exam-Oriented)

Case 1: Post-Viral Persistent Cough

Dry cough lasting 2–3 weeks
No sputum

Management:

Dextromethorphan
Reassurance

Case 2: Chronic Smoker with Productive Cough

Thick sputum

Management:

Carbocisteine
Bromhexine

Case 3: Child with Night Cough

Avoid opioids

Management:

Honey (if >1 year)
Mild antitussive if necessary

Case 4: Allergic Cough with Nasal Symptoms

Sneezing, watery eyes

Management:

Loratadine

Case 5: Severe Asthma with Cough

Wheeze + breathlessness

Management:

Salbutamol
Budesonide

Pharmacological Flowchart (Conceptual)

Dry Cough

→ Suppress reflex
→ Use: Antitussives

Productive Cough

→ Enhance mucus clearance
→ Use: Expectorants / Mucolytics

Allergic Cough

→ Block histamine
→ Use: Antihistamines

Bronchospasm Cough

→ Dilate airways
→ Use: Bronchodilators

Memory Tricks (Very High Yield)

1. Dry vs Wet Rule

Dry = Don’t cough → Suppress (Dextromethorphan)
Wet = Want cough → Clear (Guaifenesin)

2. Mucolytics Mnemonic

“ABC of mucus”

A → Acetylcysteine
B → Bromhexine
C → Carbocisteine

3. Opioid Danger Rule

Codeine → C for Child contraindicated

4. Asthma Cough Rule

“S for Spasm → S for Salbutamol”
→ Salbutamol

Drug Comparison (Advanced Table)

Feature	Dextromethorphan	Codeine	Benzonatate
Type	Central	Central opioid	Peripheral
Sedation	Mild	High	Minimal
Addiction	No	Yes	No
Use	Dry cough	Severe cough	Irritative cough

Integrated Pharmacology with Pathology

Acute Bronchitis

Productive cough
Use:
- Guaifenesin
- Ambroxol

Pneumonia

Productive cough + fever
Use:
- Amoxicillin

Asthma

Dry cough + wheeze
Use:
- Salbutamol

GERD-Related Cough

Night cough
Treatment:
- Proton pump inhibitors (not antitussives)

Advanced Drug Insights

Why Antitussives Are Harmful in Productive Cough

Suppress mucus clearance
Increase infection risk
Lead to airway obstruction

Why Hydration is Important

Enhances mucolytic effect
Reduces sputum viscosity

Why Antibiotics Are Overused

Most coughs are viral
Leads to resistance

Rapid Revision Sheet

Dry cough → Dextromethorphan
Productive cough → Guaifenesin
Thick mucus → Acetylcysteine
Wheeze → Salbutamol
Allergy → Loratadine
Severe cough → Codeine (not in children)

Trick Clinical Questions (Exam Traps)

Q: Cough + sputum + give antitussive? → ❌ Wrong
Q: Child with cough → avoid codeine
Q: Thick mucus → choose mucolytic, not suppressant
Q: Wheeze present → bronchodilator first

Ultra–High Yield Revision Tables (Exam Focus)

Classification at a Glance

Class	Drugs	Main Use
Antitussives	Dextromethorphan, Codeine	Dry cough
Expectorants	Guaifenesin	Productive cough
Mucolytics	Acetylcysteine, Ambroxol	Thick sputum
Antihistamines	Loratadine, Chlorpheniramine	Allergic cough
Bronchodilators	Salbutamol	Asthma-related cough

Viva Questions and Answers

Q1: What is the drug of choice for dry cough?

Answer:

Dextromethorphan

Q2: Why should antitussives be avoided in productive cough?

Answer:

They suppress cough reflex
Lead to retention of secretions
Increase risk of infection

Q3: Name a mucolytic drug and its mechanism

Answer:

Acetylcysteine
Breaks disulfide bonds in mucus

Q4: Which drug is contraindicated in children?

Answer:

Codeine

Q5: Drug used in cough with bronchospasm?

Answer:

Salbutamol

Short Notes for Exams

Antitussives

Used in dry cough
Act centrally or peripherally
Example:
- Dextromethorphan
- Codeine

Expectorants

Increase bronchial secretion
Facilitate mucus removal
Example:
- Guaifenesin

Mucolytics

Reduce mucus viscosity
Improve airway clearance

Examples:

Acetylcysteine
Bromhexine

Antihistamines

Used in allergic cough
Reduce postnasal drip

Examples:

Loratadine

Bronchodilators

Used in cough with wheeze
Relax bronchial muscles

Example:

Salbutamol

Mechanism-Based Understanding (Deep Concept)

Stepwise Drug Action in Cough

Irritation in airway
Signal via vagus nerve
Cough center activation
Expulsion of air

Drug Action Points

Central → suppress cough center
- Dextromethorphan
Peripheral → reduce receptor sensitivity
- Benzonatate
Mucus → reduce viscosity
- Acetylcysteine

Integrated Clinical Approach (Very High Yield)

Step 1: Identify Type

Type	Features	Treatment
Dry	No sputum	Antitussive
Productive	Sputum present	Expectorant

Step 2: Identify Cause

Cause	Treatment
Allergy	Loratadine
Asthma	Salbutamol
Infection	Amoxicillin

Advanced Exam Pearls

Dextromethorphan → no analgesia, no addiction
Codeine → strong but dangerous in children
Acetylcysteine → also antidote for paracetamol poisoning
Guaifenesin → increases secretion, not decreases
Salbutamol → best for wheezing cough

Rapid Fire Revision (Last-Minute)

Dry cough → Dextromethorphan
Wet cough → Guaifenesin
Thick mucus → Acetylcysteine
Wheeze → Salbutamol
Allergy → Loratadine
Child → Avoid Codeine

Clinical Pitfalls (Important)

Giving cough suppressants in pneumonia ❌
Ignoring red flag symptoms ❌
Using antibiotics unnecessarily ❌
Not differentiating cough type ❌

Advanced Pharmacology Insight (Concept Builder)

Why Dextromethorphan is Preferred Over Codeine

No respiratory depression
No addiction
Safer in general population

Why Mucolytics Work Better with Fluids

Water reduces mucus thickness
Enhances drug action

Why First-Generation Antihistamines Cause Sedation

Cross blood-brain barrier
Block central histamine receptors

Mini Clinical Algorithms

Algorithm 1: Dry Cough

→ Start with

Dextromethorphan

→ If severe

Codeine

Algorithm 2: Productive Cough

→ Start with

Guaifenesin

→ Add

Acetylcysteine

Algorithm 3: Wheezy Cough

→ Use

Salbutamol

→ Add steroid if needed

Ultra Short Notes (1-Minute Revision)

Antitussive → suppress cough
Expectorant → increase mucus
Mucolytic → thin mucus
Antihistamine → allergy
Bronchodilator → wheeze

One-Page Exam Cheat Sheet (Ultra-Condensed)

Core Rule

Dry cough → Suppress
Wet cough → Clear

Drug of Choice Summary

Condition	Drug
Dry cough	Dextromethorphan
Severe dry cough	Codeine
Productive cough	Guaifenesin
Thick sputum	Acetylcysteine
Allergic cough	Loratadine
Wheezing cough	Salbutamol

Mnemonics for Quick Recall

1. “DGC ALS” Rule

D → Dextromethorphan
G → Guaifenesin
C → Codeine
A → Acetylcysteine
L → Loratadine
S → Salbutamol

2. “3 M Rule” for Mucus

Moist → Mobilize → Remove
Drugs:
- Guaifenesin
- Acetylcysteine

Diagram-Style Flowchart (Exam Friendly)

Cough Management Flow

Cough → Identify Type

→ Dry
→ Dextromethorphan

→ Productive
→ Guaifenesin
→ Acetylcysteine

→ Wheeze
→ Salbutamol

→ Allergy
→ Loratadine

Rapid Comparison (Must Remember)

Feature	Dextromethorphan	Codeine
Addiction	No	Yes
Sedation	Mild	High
Safety	High	Low (children)
Use	First-line	Severe only

Top 10 Exam Pearls

Dry cough → Dextromethorphan
Productive cough → Never suppress
Codeine → Avoid in children
Acetylcysteine → Breaks disulfide bonds
Guaifenesin → Increases secretions
Salbutamol → Cough + wheeze
Loratadine → Non-sedating antihistamine
Antibiotics → Only if bacterial
Hydration → Essential for mucus clearance
Chronic cough → Think asthma, GERD, postnasal drip

Spot Diagnosis → Drug (Very High Yield)

Night dry cough → Dextromethorphan
Thick sticky sputum → Acetylcysteine
Sneezing + cough → Loratadine
Wheeze + cough → Salbutamol

Super Short Viva Lines

“Antitussives suppress cough reflex.”
“Expectorants increase bronchial secretion.”
“Mucolytics reduce sputum viscosity.”
“Bronchodilators relieve bronchospasm.”

Common Examiner Traps

Giving codeine in child ❌
Suppressing productive cough ❌
Using antibiotics in viral cough ❌
Ignoring wheezing → bronchodilator needed ❌

Final Rapid Algorithm (Memory Lock)

Cough → Type → Cause → Drug

Dry → suppress → Dextromethorphan
Wet → clear → Guaifenesin
Thick → break → Acetylcysteine
Wheeze → open → Salbutamol
Allergy → block → Loratadine

Ultra-Fast Recall (10-Second Revision)

Dry → Dextro
Wet → Guaifenesin
Thick → Acetylcysteine
Wheeze → Salbutamol
Allergy → Loratadine
Severe → Codeine (avoid kids)

Detailed Mechanisms of Action (Deep Pharmacology)

Central Antitussives

Dextromethorphan

Acts on medullary cough center
NMDA receptor antagonism
Sigma receptor activation
Raises cough threshold without affecting respiration

Codeine

μ-opioid receptor agonist
Direct suppression of cough center
Also causes sedation and analgesia

Peripheral Antitussives

Benzonatate

Blocks stretch receptors in bronchi
Reduces afferent signals via vagus nerve

Mechanism of Mucolytics

Acetylcysteine

Breaks disulfide bonds in mucoproteins
Converts thick mucus → thin, easily removable

Bromhexine

Increases lysosomal enzyme activity
Enhances mucus breakdown

Ambroxol

Stimulates surfactant production
Improves mucociliary clearance

Receptor-Level Understanding

Drug	Target
Dextromethorphan	NMDA, Sigma
Codeine	μ-opioid
Salbutamol	β2 receptor
Antihistamines	H1 receptor

Pathophysiology-Based Drug Selection

Dry Irritative Cough

No mucus
Cause: viral irritation

Drug:

Dextromethorphan

Productive Cough

Mucus present

Drugs:

Guaifenesin
Acetylcysteine

Allergic Cough

Histamine-mediated

Drug:

Loratadine

Bronchospasm-Related Cough

Narrowed airways

Drug:

Salbutamol

Pharmacokinetics (Important for Exams)

Dextromethorphan

Oral absorption
Hepatic metabolism
Duration: 4–6 hours

Codeine

Prodrug → converted to morphine
CYP2D6 dependent
Variable response in patients

Acetylcysteine

Oral or inhalational
Rapid onset in lungs

Adverse Effects (Detailed)

Opioids (Codeine)

Respiratory depression
Constipation
Dependence

Antihistamines (First Generation)

Sedation
Dry mouth
Blurred vision

Bronchodilators

Tremor
Tachycardia

Mucolytics

Nausea
Bronchospasm (rare with inhaled forms)

Drug Interactions (High Yield)

Dextromethorphan + MAO inhibitors → Serotonin syndrome
Theophylline + antibiotics → toxicity
Antihistamines + alcohol → excessive sedation

Contraindications

Codeine

Children
Respiratory depression
Head injury

Antihistamines

Glaucoma
Prostatic hypertrophy

Theophylline

Cardiac arrhythmias
Seizure disorders

Evidence-Based Prescribing

Acute Viral Cough

No antibiotics
Symptomatic treatment only

Chronic Cough (>8 weeks)

Investigate cause
Avoid blind treatment

Pediatric Guidelines

Avoid codeine
Avoid combination cough syrups in young children

Recent Advances in Cough Pharmacology

P2X3 Receptor Antagonists

Target sensory nerves
Reduce chronic refractory cough

Neuromodulators

Gabapentin (selected cases)

Clinical Reasoning (Exam Insight)

Why Not Suppress Productive Cough?

Mucus acts as infection reservoir
Needs clearance

Why Night Cough Needs Suppression?

Disturbs sleep
No productive function

Why Bronchodilator in Cough?

Treats underlying bronchospasm
Not just symptom

Integrated Case Discussion

Case: 35-year-old with cough + wheeze + night symptoms

Diagnosis: Asthma

Treatment:

Salbutamol
Budesonide

Case: Thick sputum + chest congestion

Diagnosis: Bronchitis

Treatment:

Acetylcysteine
Guaifenesin

Ultimate Memory Map

Cough Drugs = 5 Groups

Suppress → Dextromethorphan
Opioid → Codeine
Clear → Guaifenesin
Break → Acetylcysteine
Open → Salbutamol

Final High-Yield Integration

Always treat cause first
Choose drug based on type of cough
Avoid polypharmacy in children
Remember mechanism = exam key

International Guidelines and Evidence-Based Recommendations

Approach According to World Health Organization

Most acute coughs are viral → no antibiotics required

Emphasis on symptomatic relief + hydration
Avoid irrational polypharmacy, especially in children

Approach According to National Institute for Health and Care Excellence

Acute cough (<3 weeks):
- No routine antibiotics
- Self-limiting
Chronic cough (>8 weeks):
- Investigate underlying cause before treatment

Special Disease-Based Drug Use

Cough in Asthma

Dry cough + wheezing

Drugs:

Salbutamol
Budesonide

Cough in Chronic Obstructive Pulmonary Disease

Productive cough

Drugs:

Carbocisteine
Theophylline

Cough in Gastroesophageal Reflux Disease

Night cough

Treatment:

Proton pump inhibitors
Lifestyle changes

Cough in Tuberculosis

Chronic cough + weight loss

Important:

Avoid symptomatic suppression
Treat underlying disease

Pediatric Cough Management (Detailed)

Key Principles

Avoid opioids (e.g., Codeine)
Avoid unnecessary combinations
Prefer non-drug therapy first

Safe Options

Honey (>1 year)
Dextromethorphan (with caution)
Steam inhalation

Dangerous Practices

OTC cough syrups in infants ❌
Sedative antihistamines misuse ❌

Geriatric Considerations

Increased sensitivity to drugs
Avoid sedating agents
Monitor for drug interactions

Drug Formulations and Routes

Oral Syrups

Most common
Easy for children

Tablets/Capsules

Adults preferred

Inhalation/Nebulization

Acetylcysteine
Salbutamol

Fixed Dose Combination (FDC) Problems

Why FDCs Are Controversial

Irrational combinations
Increased side effects
Mask underlying disease

Example of Irrational Use

Antitussive + expectorant together ❌
(One suppresses, other promotes cough)

Pharmacoeconomics (Cost Consideration)

Simple drugs like Guaifenesin are affordable
Newer agents (P2X3 antagonists) are expensive
Avoid unnecessary prescriptions

Public Health Perspective

Overuse of antibiotics → resistance
Self-medication → misuse
Education needed on cough types

Clinical Red Flag Protocol

If patient presents with:

Hemoptysis
Weight loss
Persistent fever
Chronic cough

→ Investigate before prescribing drugs

Research and Future Trends

New Drug Targets

Sensory nerve blockers
Neurogenic cough pathways

Promising Drugs

P2X3 receptor antagonists
Better non-sedating antitussives

Comparative Clinical Effectiveness

Condition	Best Drug Class
Dry cough	Antitussives
Productive cough	Expectorants
Thick sputum	Mucolytics
Allergy	Antihistamines
Wheeze	Bronchodilators

Ethical Prescribing

Treat cause, not just symptom
Avoid unnecessary drugs
Educate patient

Clinical Integration Summary

Identify cough type
Identify cause
Choose correct drug class
Avoid harmful combinations
Monitor response

Advanced Clinical Pearls

Persistent cough → think serious disease
Night cough → often asthma or GERD
Productive cough → never suppress
Pediatric cough → minimal drugs

Ultra-Advanced Insight (Conceptual)

Cough is not just a symptom — it is a neuro-reflex disorder involving:

Sensory nerves
Brainstem integration
Motor response

Future therapies target neural pathways rather than mucus alone.

Drug–Disease Interaction Matrix (Advanced Integration)

Disease	Type of Cough	Preferred Drugs	Avoid
Asthma	Dry + wheeze	Salbutamol, Budesonide	Strong antitussives alone
Bronchitis	Productive	Guaifenesin, Ambroxol	Codeine
Pneumonia	Productive + fever	Amoxicillin	Antitussives
Allergic Rhinitis	Dry + sneezing	Loratadine	Antibiotics
COPD	Chronic productive	Carbocisteine	Sedatives

Stepwise Clinical Prescription Writing (Practical Approach)

Step 1: Diagnosis

Identify type of cough
Identify cause

Step 2: Drug Selection

Example Prescription (Dry Cough):

Dextromethorphan syrup
Dose: 10 ml TDS

Example Prescription (Productive Cough):

Guaifenesin
- Ambroxol

Example Prescription (Asthmatic Cough):

Salbutamol inhaler
- Budesonide

Drug Selection in Special Situations

Pregnancy

Prefer non-drug therapy
Use drugs only if necessary
Safer options:
- Dextromethorphan (with caution)

Lactation

Avoid sedative drugs
Monitor infant

Renal Impairment

Dose adjustment required
Avoid accumulation drugs

Hepatic Disease

Drugs metabolized in liver → caution
e.g., Dextromethorphan

Adverse Drug Reaction Table

Drug	Major Side Effect
Dextromethorphan	Drowsiness
Codeine	Respiratory depression
Guaifenesin	Nausea
Acetylcysteine	Bronchospasm
Salbutamol	Tachycardia

Drug Safety Alerts

High-Risk Drugs

Codeine → respiratory depression
Theophylline → toxicity

Safe First-Line Drugs

Dextromethorphan
Guaifenesin

Practical Clinical Pearls

Always ask about sputum
Always check wheezing
Always rule out red flags

Clinical Decision Tree (Advanced)

Patient with Cough →

→ Sputum present?
Yes → Expectorant/Mucolytic
→ Guaifenesin
→ Acetylcysteine

No → Dry cough
→ Dextromethorphan

→ Wheeze present?
Yes →
→ Salbutamol

→ Allergy signs?
Yes →
→ Loratadine

Common Prescription Errors (Clinical Reality)

Writing multiple cough syrups together ❌
Not adjusting dose in children ❌
Ignoring drug interactions ❌

Integrated Pharmacology Summary Table

Class	Mechanism	Example
Antitussive	Suppress cough center	Dextromethorphan
Expectorant	Increase secretion	Guaifenesin
Mucolytic	Break mucus	Acetylcysteine
Bronchodilator	Relax airway	Salbutamol
Antihistamine	Block histamine	Loratadine

Clinical Reasoning Framework (Expert Level)

When treating cough, always think in this order:

Is cough protective or harmful?
Is suppression needed?
Is mucus clearance needed?
Is underlying disease treated?

Advanced OSCE Scenario

Scenario:

Patient presents with:

Cough + sputum + fever

Approach:

Suspect infection
Avoid antitussives
Start:
- Amoxicillin
- - Guaifenesin

Real-Life Clinical Tip

If patient says: “I have phlegm”
→ NEVER give cough suppressants

Final Concept Reinforcement

Cough treatment is not about stopping cough —
it is about correcting the underlying mechanism.

Toxicology and Overdose of Cough Drugs

Opioid Antitussives Overdose

Codeine

Features:

Respiratory depression
Pinpoint pupils
Coma

Management:

Airway support
Antidote: Naloxone

Non-Opioid Antitussive Overdose

Dextromethorphan

Features:

Confusion
Hallucinations
Ataxia

Important:

Abuse potential in adolescents

Methylxanthine Toxicity

Theophylline

Features:

Seizures
Arrhythmias
Vomiting

Drug Abuse and Misuse

Commonly Abused Cough Drugs

Dextromethorphan → “robotripping”
Codeine → addiction

Public Health Concern

OTC availability → misuse
Especially in adolescents

Regulatory Control and Restrictions

Many countries restrict codeine-containing syrups
Pediatric use warnings for cough syrups
Labeling required for sedative effects

Herbal and Alternative Remedies

Common Natural Options

Honey → demulcent
Ginger → anti-inflammatory
Tulsi (Holy basil) → soothing effect

Scientific View

Mild benefit
Not substitute for medical therapy

Patient Counseling Points

Key Advice

Identify cough type before medication
Do not self-medicate unnecessarily
Complete prescribed course

Specific Counseling

For Antitussives:

Use only for dry cough

For Mucolytics:

Drink plenty of water

For Bronchodilators:

Use inhaler correctly

Inhaler Technique (Clinical Skill)

Steps:

Shake inhaler
Exhale fully
Press + inhale slowly
Hold breath for 10 seconds

Adherence Issues

Patients stop drugs early
Incorrect dosing
Overuse of syrups

Polypharmacy Risks

Multiple drugs → increased side effects
Drug interactions
Confusion in dosing

Clinical Audit Points

Was cough type assessed?
Was correct drug class used?
Were red flags ruled out?

Rational Use of Medicines

Principles

Right drug
Right dose
Right duration
Right patient

Environmental and Lifestyle Factors

Important Triggers

Smoking
Pollution
Allergens

Advice

Avoid irritants
Use mask if needed
Maintain hydration

Cough in Special Clinical Settings

ICU Patients

Often require airway suction
Pharmacological role limited

Post-Surgical Patients

Pain → reduced coughing
Risk of secretion retention

Future Directions in Cough Treatment

Target-Based Therapy

Neural pathway blockers
Receptor-specific drugs

Personalized Medicine

Based on patient genetics
Example: Codeine metabolism variability

Integration with Clinical Medicine

Multidisciplinary Approach

Physician
Pharmacist
Respiratory therapist

Final Concept Map (Ultimate Understanding)

Cough Management = 4 Core Actions

Suppress (Dry cough)
- Dextromethorphan
Clear (Productive cough)
- Guaifenesin
Break (Thick mucus)
- Acetylcysteine
Open (Bronchospasm)
- Salbutamol

Master-Level Clinical Insight

Treating cough is not suppression alone
It is mechanism-based therapy
Always balance benefit vs risk

Final High-Yield Line

“Correct drug depends on cough type — not just the symptom.”

Detailed Drug Monographs (Exam + Clinical Depth)

Dextromethorphan

Class: Non-opioid central antitussive

Mechanism:

Acts on medullary cough center
NMDA receptor antagonism

Indications:

Dry, irritating cough
Post-viral cough

Dose:

Adults: 10–20 mg every 4–6 hours

Adverse Effects:

Mild drowsiness
Dizziness

Special Points:

No addiction at therapeutic dose
High dose → abuse potential

Codeine

Class: Opioid antitussive

Mechanism:

μ-receptor agonist

Indications:

Severe dry cough

Adverse Effects:

Respiratory depression
Constipation
Dependence

Contraindications:

Children
Asthma

Guaifenesin

Class: Expectorant

Mechanism:

Increases respiratory secretions

Indications:

Productive cough

Adverse Effects:

Nausea
GI upset

Acetylcysteine

Class: Mucolytic

Mechanism:

Breaks disulfide bonds

Indications:

Thick sputum
Paracetamol toxicity

Adverse Effects:

Bronchospasm (rare)

Salbutamol

Class: Bronchodilator

Mechanism:

β2 receptor stimulation

Indications:

Asthma
Wheeze with cough

Adverse Effects:

Tremor
Tachycardia

Loratadine

Class: Antihistamine

Mechanism:

H1 receptor blockade

Indications:

Allergic cough

Advantages:

Non-sedating

Comparative Pharmacology Table (Deep Understanding)

Drug	Site of Action	Main Effect	Key Risk
Dextromethorphan	CNS	Suppress cough	Abuse (high dose)
Codeine	CNS	Strong suppression	Respiratory depression
Benzonatate	Peripheral	Reduce reflex	Choking risk
Guaifenesin	Airways	Increase mucus	Mild GI upset
Acetylcysteine	Mucus	Break mucus	Bronchospasm

Receptor-Level Pharmacology (Advanced)

CNS Targets

NMDA receptors → Dextromethorphan
μ-opioid receptors → Codeine

Airway Targets

β2 receptors → Salbutamol
Mucoproteins → Acetylcysteine

Advanced Clinical Integration

When Multiple Mechanisms Are Present

Example:

Cough + sputum + wheeze

Treatment:

Guaifenesin
Salbutamol

Stepwise Rational Therapy

Step 1: Identify mechanism

Irritation → suppress
Mucus → clear
Allergy → block
Spasm → dilate

Step 2: Select minimal drugs

Avoid unnecessary combinations

Step 3: Monitor response

Improvement in 3–5 days

Advanced Clinical Scenarios

Scenario: Chronic dry cough + normal chest exam

Likely causes:

Post-viral
GERD
ACE inhibitor

Management:

Dextromethorphan
Treat underlying cause

Scenario: Thick sputum + chest congestion

Management:

Acetylcysteine
Increase hydration

High-Yield Differences (Exam Favorite)

Expectorant vs Mucolytic

Feature	Expectorant	Mucolytic
Action	Increase secretion	Break mucus
Example	Guaifenesin	Acetylcysteine
Use	Mild cough	Thick sputum

Clinical Judgment Tips

Always match drug with pathophysiology
Avoid treating symptom blindly
Evaluate patient thoroughly

Expert-Level Insight

Cough drugs act at three major levels:

Central nervous system
Airway receptors
Mucus properties

Effective therapy often targets more than one level.

Ultra-Final Memory Grid

Problem	Drug Action	Example
Dry cough	Suppress	Dextromethorphan
Severe cough	Strong suppression	Codeine
Productive	Clear mucus	Guaifenesin
Thick mucus	Break mucus	Acetylcysteine
Wheeze	Open airway	Salbutamol

Core Clinical Principle (Highest Yield)

“Right drug = Right mechanism = Right outcome”

Advanced Pharmacodynamics of Cough Drugs

Central Neural Control of Cough

The cough reflex is regulated by a complex neural network involving:

Sensory receptors in airway
Afferent vagal pathways
Central integration in medulla
Efferent motor response

Central Modulation by Antitussives

Dextromethorphan

Inhibits excitatory neurotransmission in cough center
Reduces neuronal sensitivity

Codeine

Activates inhibitory pathways
Suppresses brainstem cough circuits

Peripheral Mechanisms in Detail

Sensory Receptor Modulation

Benzonatate

Blocks stretch receptors
Prevents initiation of cough reflex

Mucus Modification

Acetylcysteine

Cleaves disulfide bonds
Decreases mucus elasticity

Guaifenesin

Increases hydration of mucus
Enhances mucociliary clearance

Neurogenic Cough (Emerging Concept)

Pathophysiology

Hypersensitive cough reflex
Overactive sensory nerves

New Targets

P2X3 receptors
TRP channels

Clinical Phenotypes of Cough

1. Acute Cough

Duration: <3 weeks
Usually viral

2. Subacute Cough

Duration: 3–8 weeks
Post-infectious

3. Chronic Cough

Duration: >8 weeks
Needs evaluation

Chronic Cough Causes and Drugs

Cause	Drug
Asthma	Salbutamol
GERD	Proton pump inhibitors
Postnasal drip	Loratadine

Pharmacogenomics (Very Advanced)

Codeine Metabolism

Codeine

Converted to morphine via CYP2D6

Genetic Variations:

Poor metabolizers → no effect
Ultra-rapid metabolizers → toxicity

Drug Delivery Innovations

Nebulized Therapy

Direct lung delivery
Faster action

Examples:

Salbutamol
Acetylcysteine

Sustained-Release Formulations

Longer duration
Better compliance

Cough Reflex Sensitization

Mechanism

Repeated irritation → hypersensitivity
Leads to chronic cough

Treatment Strategy

Neuromodulators
Targeted therapy

Advanced Clinical Correlations

ACE Inhibitor-Induced Cough

Cause:

Increased bradykinin

Management:

Stop ACE inhibitor
Switch to ARB

Post-Infectious Cough

Persistent dry cough

Treatment:

Dextromethorphan

Clinical Examination Focus

Key Questions

Duration of cough
Presence of sputum
Associated symptoms

Key Signs

Wheeze
Crackles
Fever

Integrated Therapeutic Strategy

Combine Approaches

Pharmacological
Non-pharmacological
Treat underlying cause

Advanced Drug Selection Logic

If cough is:

Reflex-driven → suppress
Secretion-driven → clear
Allergy-driven → block
Spasm-driven → dilate

Real-World Clinical Reasoning

Example Case

Patient:

Chronic cough
No sputum
Normal X-ray

Likely: Neurogenic cough

Management:

Antitussives
Neuromodulators

Final Integration Table

Mechanism	Drug
Central suppression	Dextromethorphan
Peripheral inhibition	Benzonatate
Mucus breakdown	Acetylcysteine
Secretion increase	Guaifenesin
Bronchodilation	Salbutamol

Master-Level Summary Concept

Cough treatment involves three major targets:

Brain (central control)
Airways (receptors & muscles)
Secretions (mucus)

Ultimate Clinical Insight

“Not all coughs should be stopped — some must be helped.”

Long Essay–Style Answer (Exam-Oriented)

Drugs Used in Cough

Cough is a protective reflex mechanism that helps clear the respiratory tract of irritants, secretions, and foreign particles. Pharmacological treatment is aimed either at suppressing the cough reflex or facilitating the removal of bronchial secretions, depending on the nature of the cough.

Classification

1. Antitussives

These drugs suppress the cough reflex and are used in dry (non-productive) cough.

A. Centrally Acting

Codeine
Dextromethorphan

Mechanism:

Act on cough center in medulla
Increase threshold for cough

B. Peripherally Acting

Benzonatate

Mechanism:

Reduce sensitivity of airway receptors

2. Expectorants

Guaifenesin

Mechanism:

Increase bronchial secretions
Facilitate expulsion of mucus

3. Mucolytics

Acetylcysteine
Bromhexine

Mechanism:

Reduce viscosity of mucus
Break down mucoproteins

4. Bronchodilators

Salbutamol

Mechanism:

Relax bronchial smooth muscle
Improve airflow

5. Antihistamines

Loratadine

Mechanism:

Block histamine receptors
Reduce allergic cough

Therapeutic Approach

Dry cough → Antitussives
Productive cough → Expectorants/Mucolytics
Allergic cough → Antihistamines
Asthmatic cough → Bronchodilators

Adverse Effects

Sedation (antihistamines, opioids)
Respiratory depression (opioids)
Nausea (expectorants)
Tachycardia (bronchodilators)

Contraindications

Codeine in children
Antihistamines in glaucoma
Theophylline in arrhythmias

Rational Use

Identify type of cough before treatment
Avoid suppressing productive cough
Use antibiotics only when indicated

OSCE Long Case Format

Step 1: History

Duration of cough
Type (dry/productive)
Associated symptoms

Step 2: Examination

Chest auscultation
Signs of infection or allergy

Step 3: Diagnosis

Identify underlying cause

Step 4: Management

Example:

Dry cough → Dextromethorphan
Productive cough → Guaifenesin

Short Essay (5-Mark Answer)

Antitussives:

Suppress cough reflex
Example: Dextromethorphan

Expectorants:

Increase secretion
Example: Guaifenesin

Mucolytics:

Reduce viscosity
Example: Acetylcysteine

Ultra-Structured Answer for Exams

Definition

Cough is a reflex action to clear airway.

Classification

Antitussives
Expectorants
Mucolytics
Bronchodilators
Antihistamines

Mechanism

Central suppression
Peripheral action
Mucus modification

Uses

Dry cough
Productive cough
Allergic cough

Side Effects

Sedation
GI upset
Tachycardia

High-Yield Examiner Points

Always classify drugs
Mention mechanism
Give examples
Write rational use

Integrated Revision Block

Dry → Dextromethorphan
Wet → Guaifenesin
Thick → Acetylcysteine
Wheeze → Salbutamol
Allergy → Loratadine

Final Clinical Reinforcement

Match drug with cough type
Avoid unnecessary drugs
Focus on underlying cause

Case-Based Long Questions (Exam Practice)

Case 1

A 25-year-old patient presents with dry cough for 5 days, worse at night, no sputum, no fever.

Questions:

Diagnosis?
Drug of choice?
Mechanism of action?

Answer:

Diagnosis: Acute viral dry cough
Drug: Dextromethorphan
Mechanism: Suppresses cough center in medulla

Case 2

A 40-year-old smoker presents with productive cough and thick sputum.

Questions:

Drug of choice?
Why not antitussives?

Answer:

Drug: Acetylcysteine + Guaifenesin
Reason: Suppressing cough leads to mucus retention

Case 3

Child with cough and mild fever.

Question:

Which drug should be avoided?

Answer:

Codeine

Case 4

Patient presents with cough + wheezing.

Answer:

Salbutamol

OSCE Station Example

Scenario:

Patient complains of cough for 2 weeks.

Tasks:

Take history
Identify type
Suggest treatment

Model Answer

History Points:

Duration
Sputum
Fever
Allergy

Management:

Dry → Dextromethorphan
Productive → Guaifenesin

Clinical Problem-Solving Questions

Q1

Cough + night symptoms + no sputum
→ Likely cause?
→ Answer: Asthma / post-viral

Q2

Cough + sputum + fever
→ Treatment?
→ Amoxicillin

Q3

Cough + sneezing + watery eyes
→ Treatment?
→ Loratadine

Frequently Asked Exam Questions

1. Why avoid antitussives in productive cough?

Prevent mucus clearance

2. Why is codeine contraindicated in children?

Risk of respiratory depression

3. Which drug breaks mucus bonds?

Acetylcysteine

Integrated Grand Table (Ultimate Revision)

Condition	Drug	Mechanism
Dry cough	Dextromethorphan	Central suppression
Severe cough	Codeine	Opioid action
Productive	Guaifenesin	Increase secretion
Thick mucus	Acetylcysteine	Break bonds
Wheeze	Salbutamol	Bronchodilation
Allergy	Loratadine	H1 blockade

Ultra-High Yield Quick Facts

Dextromethorphan → safest antitussive
Codeine → strongest but risky
Guaifenesin → most used expectorant
Acetylcysteine → mucolytic + antidote
Salbutamol → cough with wheeze

Trick Questions (Exam Traps)

Trap 1

Productive cough → give antitussive
❌ Wrong

Trap 2

Child with cough → give codeine
❌ Wrong

Trap 3

All cough → antibiotics
❌ Wrong

Final Integrated Clinical Summary

Cough Management Pyramid

Top → Treat cause
Middle → Select correct drug class
Bottom → Supportive care

Golden Rule for Exams

“First identify cough type, then choose drug.”

Final Rapid Recall Block

Dry → Dextromethorphan
Wet → Guaifenesin
Thick → Acetylcysteine
Wheeze → Salbutamol
Allergy → Loratadine

Ultimate Closing Concept (Still No Conclusion)

Cough pharmacology is mechanism-based, not symptom-based, and proper drug selection depends on understanding physiology, pathology, and pharmacology together.

Drugs Used In Cough PDF File

PDF File Is At The End Of The Article 👇👇

Drugs Used in Cough

Introduction

Classification of Drugs Used in Cough

1. Antitussives (Cough Suppressants)

A. Centrally Acting Antitussives

B. Peripherally Acting Antitussives

2. Expectorants and Mucolytics

A. Expectorants

B. Mucolytics

3. Bronchodilators in Cough

4. Antihistamines in Cough

5. Corticosteroids

6. Antibiotics (When Infection is Present)

7. Demulcents

8. Combination Preparations

Factors Affecting Drug Selection

Special Considerations in Children

Adverse Effects of Cough Drugs

Non-Pharmacological Measures

Pathophysiological Basis of Drug Use

Emerging Therapies

Detailed Pharmacology of Antitussives

Centrally Acting Opioid Antitussives

Codeine

Pholcodine

Non-Opioid Central Antitussives

Dextromethorphan

Noscapine

Peripheral Antitussives in Detail

Benzonatate

Levodropropizine

Expectorants: Advanced Concepts

Guaifenesin

Ammonium chloride

Potassium iodide

Mucolytics: In-Depth

Acetylcysteine

Bromhexine

Ambroxol

Carbocisteine

Bronchodilators and Their Role in Cough

Salbutamol

Terbutaline

Theophylline

Antihistamines in Cough Management

Diphenhydramine

Chlorpheniramine

Loratadine

Corticosteroids: Expanded Discussion

Prednisolone

Budesonide

Antibiotics in Cough

Amoxicillin

Azithromycin

Fixed Dose Combinations (FDCs)

Clinical Approach to Cough Treatment

Dry Cough

Productive Cough

Allergic Cough

Asthmatic Cough

Chronic Cough: Pharmacological Approach

Special Populations

Elderly

Pregnancy

Pediatric Considerations

Drug Interactions

Toxicity and Overdose

Pharmacological Pearls (Exam-Oriented)

Dosage Regimens of Common Drugs Used in Cough

Antitussives

Dextromethorphan

Codeine

Benzonatate

Expectorants

Guaifenesin

Mucolytics

Acetylcysteine

Ambroxol