Dr. Kashif Hussain

COUGHProtective mechanismForceful expiration to remove foreign body,mucus or

secretions

Cough Reflex

1) cough receptors

airways,pleura, upper GIT,pericardium,ears and diaphragm

2) afferent nerve

3) cough center

4) efferent nerves

5) effectors

Types of CoughDry Cough

Productive cough

Acute cough < 3 wks ( acute RTI)

Subacute cough3-8 wks( BHR )

Chronic cough

> 8 wks (asthma,GERD,PND)

Goals of Therapy

1.Treat underlying cause of cough

2.productive cough( Mucolytics & Expectorants)

3.suppress dry cough (Anti-tussives)

4.Bronchodilators

5.ICS

Antitussives

Central acting

Decrease sensitivity of cough center to peripheral stimuli and decrease mucosal secretion

1. OPIATES

Codeine ( GOLD STANDARD )

Pholcodine

Morphine and methadone for intractable

cough due to lung cancer

Antitussive effect occur at doses lower than those required for analgesia therefore S/E are less common but still occur and include:

1. Constipation

2. dysphoria

3. fatigue

4. addictive potential

2.Opioid derivatives

Dextromethorphan

Noscapine

Levopropoxyphene

Dextromethorphan• Synthetic derivative of morphine• Central acting• No analgesic effect in antitussive doses• Low addictive profile

• Less constipation than codeine• Significantly better S/E profile than codeine• Equally effective as codeine for cough

suppression

2.PERIPHERAL ACTING

Benzonatate

local anesthetic effect in respiratory tract and pleura

Thalidomide

Cough due to IPF(idiopathic pulmonary fibrosis).Serious S/E is teratogenicity

OTHERS

Diphenhydramine (Antihistamine)

EXPECTORANTS increase bronchial secretions and help in

expulsion of sputum

CLASSIFICATION

1.Drugs that reflexly irritate bronchial mucosa Guaifenesin (Only expectorant approved by

FDA ) Ammonium chloride Ammonium bicarbonate

2. Drugs that directly irritate bronchial mucosa

Sodium IodidePotassium Iodide

MUCOLYTICS

decrease sputum viscosity

They cause depolymerization of mucopolysaccharide protein fibers

They are useful in COPD

N-Acetylcysteine Erdosteine Bromhexine Carbocysteine in COPD Methylcysteine DNAase 1 ( dornase alfa ) in Cystic fibrosis