3. Cough
Protective reflex mechanism which removes foreign material
and excess respiratory secretion
Involuntary reflex and major defensive mechanism
Disturb patient ,its rest and sleep
4. Mechanism of Cough is complex
Central and peripheral nervous systems involved
Changes in Bronchial smooth muscle and bronchial mucosa
Is responsible
Cough centre-Medulla
Cough receptor-stretch receptor-pharynx,Larynx,Lungs
Mechanism of cough
12. Antitussives
Ideally cough should not be suppressed
Treatment of underlying cause
Drugs which suppress cough-Antitussives
M.O.A
Raise threshold & inhibit cough reflex in
cough centre in medulla
In respiratory tract reduce tussal impulse
Useful for dry cough
13. Semi synthetic opioid analgesic
Less potent than morphine
More selective for cough centre
Low dose (10 mg BD), 6hours
Anti tussive action –blocked by Naloxone
Has less addiction
S/E
Constipation ,Drowsiness, Respiratory depression
Contraindicated in bronchial asthma
Codeine
15. Noscapine
Opium alkaloids belongs to benzyl isoquinoline group
No addictive, analgesic & constipating properties
Do not interfere with mucocilliarymovement
Different mechanism
Release histamine, bronchoconstriction
S/E
Nausea, headache, tremor
Dose 15 mg
16. Dextromethorphan
D-isomer of methorphan
Raise threshold for cough centre
Antitussive action not blocked by Naloxone
M.O.A
NMDA receptor antagonist
Least addiction and constipation, Minimal drowsiness
No analgesic action, No affect on mucocilliaryaction
Uses
Use along with antihistamine and bronchodilator as suppressant
S/E
Nausea, vomiting, ataxia
Dose- 10mg TDS
18. Q.A young patient is diagnosed with asthma. His primary
symptom is frequent cough ,not bronchospasm and
wheezing.Ashthma medication started but until their
effect develop we want to suppress the cough without
running risk of suppressing ventilatory drive or causing
sedation. Which is the best drug for this?
A.Codeine
B.Dexomethorphan
C.Promethazine
D.None of the above
20. Sodium & potassium citrate or Acetate
M.O.A
Bronchial secretion by salt action
Guaiphenesin
Expectorant drug usually taken by mouth
M.O.A
Increase airway secretion and mucocilliary activity
Dose 100-200mg BD
Ammonium chloride,Ipecac
Reflexly increase respiratory secretion
Gastric irritant
21. Potassium Iodide
Direct
Indirect
Liquefaction of tenacious sputum
A/E
Metallic taste, Swelling of salivary and lacrimal gland
Hypothyroidism
Dose-300mg TDS
22. Mucolytics
Acetyl cysteine
M.O.A
Reduce viscosity of sputum by opening disulfide bond of
mucoprotein
S/E
Nausea,vomiting,stomatitis,bronchospasm,rhinorrhea
Dose 200mg
Administer directly to respiratory tract
26. Q.Which of the following statements regarding opiate action
is correct?
A. Trigger vagal reflex to suppress cough
B.Cause diarrhea
C.Stimulate production of cough
D.Suppress cough centre
27. Q.Which is NOT a mucolytic?
A.Ambroxol
B.Acetylcysteine
C.Bromhexine
D.Potassium iodide
28. Antihistamines
Added to antitussives/expectorant formulation
Relief in cough due to sedative & anticholinergic actions
Lack selectivity for cough centre
No expectorantaction
↓Secretions (anticholinergic effect)
Suitable for allergic cough but not for asthma
Ex.Chlorpheniramine, diphenhydramine, promethazine
29. Bronchodilators
M.O.A
↑Surface velocity of air flow during cough
Clear secretions of airway
Not used routinely for every type ofcough
present ( Bronchial
Use only when bronchoconstriction is
asthma)
Ex. β2-agonist (salbutamol, terbutaline)
30. Role of hydration in cough
Dehydration increase viscosity of secretion
Adequate fluid –decrease viscosity
Highly effective
Role of steam inhalation
Useful for liquefaction of tenacious sputum
Role of other agents