Cough is a protective reflex to clear irritants from the respiratory system, categorized into productive (helpful) and non-productive (harmful). Treatment options include expectorants, mucolytics, and antitussives, each serving different roles; expectorants facilitate mucus clearance, while antitussives suppress cough based on the type. Medications like codeine and dextromethorphan are highlighted for their antitussive properties, with various side effects and considerations for specific patient populations.

1. Cough and Its treatment

2. Cough
 Cough is a protective reflex to remove irritants and accumulated
secretions from respiratory passages
 Cough occurs due to stimulation of mechano- or chemoreceptors in
throat, respiratory passages or stretch receptors in the lungs.
 Cough may be useful or useless.
 Useful (productive) cough serves to drain the airway, its suppression
is not desirable, may even be harmful, except if the amount of
expectoration achieved is small compared to the effort of continuous
coughing.
 Useless (non-productive) cough should be suppressed

4. PHARYNGEAL DEMULCENTS
Sooth the throat and reduce afferent impulses from
the inflamed/irritated pharyngeal mucosa, thus
provide symptomatic relief in dry cough arising
from throat.
Lozenges
Cough drops
Linctus containing syrups
Glycerine liquorice

5. EXPECTORANTS AND MUCOLYTICS
EXPECTORANTS : increase the volume of
bronchial secretion and reduce viscosity of
sputum, and hence cough become less tiring and
productive which facilitating its removal by coughing.
MUCOLYTICS: Break thick tenacious sputum so
that sputum will come out easily with less effort

6. BRONCHIAL SECRETION ENHANCERS
Sodium and potassium citrate.
increase bronchial secretion by salt action.
KI is secreted by bronchial glands and can irritate the
airway mucosa.
ADR: Prolonged use can affect thyroid function and
produce iodism.
It is not used now.

7. BRONCHIAL SECRETION ENHANCERS
Guaiphenesin, vasaka, tolu balsum :
Plant products which are supposed to enhance
bronchial secretion and mucociliary function while
being secreted by tracheobronchial glands
Ammonium salts are nauseating—reflexly
increase respiratory secretions

8. MUCOLYTICS: BROMHEXINE &
AMBROXOL
 BROMHEXINE: Derivative of the alkaloid vasicine obtained from
Adhatoda vasica (Vasaka), is a potent mucolytic and mucokinetic
which capable of inducing thin copious bronchial secretion.
 AMBROXOL: metabolite of bromhexine having same action
 MOA: It depolymerises mucopolysaccharides directly as well as
by liberating lysosomal enzymes 4 break network of fibres in
tenacious sputum. It is particularly useful if mucus plugs are
present.
 ADR: Rhinorrhoea and Lacrimation, nausea, gastric irritation,
hypersensitivity

9. MUCOLYTICS
• ACETYLCYSTEINE
• It opens disulfide bonds in mucoproteins present in
sputum—makes it less viscid
• but has to be administered directly into the
respiratory tract.

10. MUCOLYTICS
CARBOCISTEINE
MOA: It liquefies viscid sputum in the same way as
acetyl cysteine (opens disulfide bonds) and is
administered orally (250-750 mg TDS).
CI: It may break gastric mucosal barrier
(contraindicated in peptic ulcer patients).
ADR: gastric discomfort and rashes.
USES: patients of chronic bronchitis.

11. ANTITUSSIVES
Drug used are
Opiods: Codeine, Pholcodiene
Nonopioids: Noscapine,Dextromethorphan,
Chlophendianol
Antihistamine: Chlorpheniramine, Diphenhydramine,
Promethazine
Peripherally acting: Prenoxdiazine.

12. CODEINE
opium alkaloid, qualitatively similar to and less potent
than morphine, but is more selective for cough centre.
Uses as standard antitussive; suppresses cough for 6
hours.
MOA: Act through opioid receptors in the brain
(antitussive action can be blocked by naloxone)
ADR:
A. Constipation.
B. Respiratory depression and drowsiness (At higher doses)
especially in children, Driving may be impaired.
CI: In asthmatics and in patients with diminished
respiratory
Reserve ; should be avoided in Children

13. ETHYL MORPHINE & PHOLCODEINE
ETHYLMORPHINE
It is closely related to codeine
has antitussive, respiratory depressant properties like
codeine, but is believed to be less constipating
PHOLCODEINE
It has practically no analgesic or addicting property,
similar in efficacy as antitussive to codeine and is
longer acting—acts for 12 hours

14. NOSCAPINE (NARCOTINE)
• Nonopioids equipotent antitussive as codeine
• useful in spasmodic cough.
• MOA: It depresses cough but has no narcotic,
analgesic or
• dependence inducing properties.
ADR:
Headache and nausea.
It can release histamine and produce
bronchoconstriction in asthmatic

15. NOSCAPINE (NARCOTINE)
• Nonopioids equipotent antitussive as codeine
• useful in spasmodic cough.
• MOA: It depresses cough but has no narcotic,
analgesic or
• dependence inducing properties.
ADR:
Headache and nausea.
It can release histamine and produce
bronchoconstriction in asthmatic

16. DEXTROMETHORPHAN
MOA: synthetic central NMDA (N-methyl D-aspartate)
receptor antagonist; the d-isomer has antitussive
action while I-isomer is analgesic.
Does not depress mucociliary function of the airway
mucosa
Devoid of constipating action.
Non addicting.
The antitussive action equivalent to codeine
ADR: Dizziness, nausea, drowsiness; at high doses
hallucinations and ataxia may occur.

17. NOSCAPINE (NARCOTINE)
Nonopioids equipotent antitussive as codeine
useful in spasmodic cough.
MOA: It depresses cough but has no narcotic,
analgesic or
dependence inducing properties.
ADR:
Headache and nausea.
It can release histamine and produce
bronchoconstriction in asthmatic

18. DEXTROMETHORPHAN
MOA: synthetic central NMDA (N-methyl D-aspartate)
receptor antagonist; the d-isomer has antitussive
action while I-isomer is analgesic.
does not depress mucociliary function of the airway
mucosa
devoid of constipating action.
Non addicting,
The antitussive action equivalent to codeine
ADR: Dizziness, nausea, drowsiness; at high doses
hallucinations and ataxia may occur.

19. ANTIHISTAMINE
Chlorpheniramine, Diphenhydramine,
Promethazine
Relief in cough due to their sedative and
anticholinergic actions, but lack selectivity for
the cough centre.
no expectorant property, may even reduce
secretions by anticholinergic action.
They have been specially promoted for cough
in respiratory allergic states, though their lack
of efficacy in asthma is legendary.

20. PRENOXDIAZINE
it acts peripherally which desensitizes the
pulmonary stretch receptors and reduces
tussal impulses originating in the lungs.
It is indicated in cough of bronchial origin. s
Efficacy is not impressive.