Pharmacology PPT

1. Cough
Dr Chintan Doshi

2. WHAT IS COUGH ?
• It’s a protective reflex – for expulsion of
respiratory secretions and foreign particles
from air passages
• Occurs due to stimulation of mechano- or
chemoreceptors in throat, respiratory
passages or stretch receptors in the lungs
• Cough may be useful or useless

3. Contd.
• Useless (nonproductive) cough should be
suppressed
• 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

7. Important
• The US-FDA has stopped marketing of all
expectorants, except guaiphenesin.
• Steam inhalation and proper hydration may be
more helpful in clearing airway mucus.

11. Nonopioids
• Noscapine (Narcotine)
– An opium alkaloid
– Depresses cough but has no narcotic, analgesic or
dependence
– Useful in spasmodic cough.
– Release histamine and produce
bronchoconstriction in asthmatics

12. Contd.
• Dextromethorphan
– central NMDA (N-methyl D-aspartate) receptor
antagonist
– d-isomer has antitussive action while l-isomer is
analgesic
– does not depress mucociliary function of the
airway mucosa and is practically devoid of
constipating action
– Nonaddicting
– Side effect: Dizziness, nausea, drowsiness

14. Peripherally acting antitussives
• Prenoxdiazine
• It acts peripherally
• Desensitizes the pulmonary stretch receptors
and reduces tussal impulses originating in the
lungs
• Indicated in cough of bronchial origin

15. •THANK YOU