Here is the slide on Drugs used in Cough

1. PREPARED BY:
BIKRAM ADHIKARI (3)
HUMAN BIOLOGY 7TH
BATCH
Drugs used for Cough
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2. Introduction to Cough
 Cough is the protective reflex, its purpose being expulsion
of respiratory secretions or foreign particles from lungs or
upper airway passages
 Cough may be:
 Useful (productive):
 Sputum is coughed up/drain the airway)
 Useless(nonproductive/dry)
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3. Introduction to Cough
Types of cough
 Classified based on duration, characters, quality and timing
Acute: Sudden onset/less than 3 weeks
Sub-acute: 3-8 weeks
Chronic: Longer than eight weeks
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4. Mechanism of cough
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5. Drugs for cough
Cough can be treated :
 By Nonspecific therapy
 With specific remedies(antibiotics,etc)
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6. Nonspecific therapy
1) Pharyngeal demulcents :
Lozenges, Cough drops, Linctuses containing syrup, glycerine,
liquorice
2) Expectorants (Mucokinetics)
(a)Bronchial secretion enhancers:
Sodium or Potassium citrate, Potassium iodide, Guaiphenesin (Glyceryl
guaiacolate), Balsum of Tolu, Vasaka,Ammonium chloride.
(b) Mucolytics:
Bromhexine, Ambroxol, Acetyl cysteine, Carbocisteine
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7. Nonspecific therapy
3) Antitussives (Cough centre suppressants)
(a) Opioids: Codeine, Ethylmorphine, Pholcodeine
(b) Nonopioids: Noscapine, Dextromethorphan, Chlophedianol.
(c) Antihistamines: Chlorpheniramine, Diphenhydramine, Promethazine
(d) Peripherally acting: Prenoxdiazine.
2) Adjuvant antitussives
Bronchodilators: Salbutamol, Terbutalin.
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8. Demulcents and expectorants
Pharyngeal demulcents
sooth throat
 reduce afferent impulses from the inflamed/irritated
mucosa
symptomatic relief in dry cough arising from throat
Lozenges
Cough drops
Linctuses containing syrup
Glycerine
Liquorice
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9. Demulcents and expectorants contd…
Expectorant
 Mucokinetics
 Increase bronchial secretion or reduce viscosity removal by
coughing
Two category:
 Bronchial secretion enhancer
 Mukolytics
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10. Demulcents and expectorants contd…
Bronchial secretion enhancer
 Sodium or Potassium citrate
 Potassium iodide
 Guaiphenesin(Glyceryl guaiacolate)
 Balsum of Tolu
 Vasaka
 Ammonium chloride
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11. Demulcents and expectorants contd…
Bronchial secretion enhancer
 Sodium or Potassium citrate salt action
 Potassium iodide
 Secreted by bronchial glands
 Irritate airways mucosa
 Prolonged usedisturb thyroid function iodism
 Not used now
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12. Demulcents and expectorants contd…
Bronchial secretion enhancer
 Guaiphenesin, Balsum of Tolu, Vasaka
 Plant products
 Enhance bronchial secretion
 Promotes Mucocilliary function secreted by tracheobronchial
glands
 Ammonium chloride
 Ammonium salts
 Increase respiratory secretions
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13. Demulcents and expectorants contd…
 Expectorant formulations + antitussive / antihistaminics
 US-FDA stopped marketing except Guaiphenesin
 Steam inhalation & proper hydration  clearing airways
Nonconclusive efficacy
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14. Demulcents and expectorants contd…
Mucolytics
 Bromhexine
 Ambroxol
 Acetyl cysteine
 Carbocisteine
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15. Demulcents and expectorants contd…
Mucolytics
 Bromhexine:
 Derivative of vasicine obtained from Adhatoda vasica
 Potent mucolytic and mucokinetic  induce thin copious
bronchial secretion
 Depolymerises mucopolysaccharide directly or by lysosomal
enzyme
 Dose: adult 8mg TDS side effects
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16. Demulcents and expectorants contd…
Mucolytics
 Ambroxol:
 A metabolite of bromohexine
 Dose: 15-30 mg TDS
 Mucolytic action, uses and side effects similar to bromhexine
 Acetylcysteine
 Derivative of cysteine
 Opens disulfide bonds on mucoproteins present in sputum
 Also act as antioxidants reduce airway inflammation
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17. Demulcents and expectorants contd…
Mucolytics
 Carbocysteine:
 Liquefies viscid sputum
 Administered orally (250-750 mg TDS)
 May break gastric mucosal barrier  contraindicated in peptic
ulcer
 Side effects:
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18. Antitussives
 Acts on CNS  raise threshold of cough center
 Act peripherally in respiratory tract  reduce tussal response
or both the action
 Aimed to control the cough rather than eliminate
 Used only for dry, unproductive cough or if cough is unduly
tiring, disturbs sleep /hazardous
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19. Antitussives (contd..)
Ophoids:
Codeine
 Opium alkaloid Less potent than morphine
 more selective for cough center
 standard antitussive: suppress cough for 6 hours
 Side effects:
Abuse
Constipation is main drawback
At high dose, respiratory depression and drowsiness
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20. Antitussives (contd..)
 Contraindications:
 Asthamatics
Patients with diminished respiratory reserve
Should be avoided in children
 Dose: adult 10-30mg frequently used as syrup codeine
phos. 4-8 ml
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21. Antitussives (contd..)
Ophoids:
Ethylmorphine
 Closely related to codeine which is methylmorphine
 Has antitussive, respiratory depressant properties like codeine
 Believed to be less constipating
 Dose: 10-30 mg TDS
Pholcodeine
 Similar in efficacy as antitussive to codeine
 Long acting codeine (12h)
 Dose: 10-15 mg.
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22. Antitussives (contd..)
Nonopioids:
Noscapine
 Opium alkaloid of benzoisoquinoline
 Depresses cough but lacks narcotic, analgesic or
dependence inducing properties
 Equipotent antitussive as codeine
 Useful in spasmodic cough
 Dose: 15-30 mg
 Side effect:
Headache and nausea
Can produce bronchoconstriction by stimulating histamine
release
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23. Antitussives (contd..)
Nonopioids:
Dextromethorphan
 A synthetic central NMDA (N-methyl D-aspartate) receptor
antagonist
 d-isomer has antitussive action while l-isomer is analgesic.
 Effective as codeine
 Does not depress mucociliary function of the airway mucosa
 Dose: 10–20 mg
 Side effect:
Dizziness, nausea, drowsiness
 At high doses hallucinations and ataxia may occur.
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24. Antitussives (contd..)
Nonopioids:
Chlophedianol
 A centrally acting antitussive
 Slow onset and longer duration of action.
 Dose: 20–40 mg
 Side effect:
Dryness of mouth
Vertigo
Irritability
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25. Antitussives (contd..)
Antihistamines:
H1 blockers are added to antitussive/expectorants
Afford relief in cough due to their sedative and
anticholinergic action
Lack selectivity for cough center
Have no expectorant property
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26. Antitussives (contd..)
Specially promoted for cough in respiratory allergic
states
Commonly used antihistanines:
Chlorpheniramine (2-5mg)
Diphenhydramine (15-25mg )
Promethazine (15-25mg)
Second generation antihistamines like Terfenadine,
Loratadine are ineffective
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27. Antitussives (contd..)
Peripherally acting antitussives:
Prenoxdiazine :
 Desensitize the pulmonary stretch receptors and reduce
tussal impulses originating in the lungs
 Indicated in cough of bronchial origin
 Efficacy is not impressive
 Dosage: 100-200 mgs TID-QID
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28. Adjuvant Antitussives
Bronchodilators:
 Bronchospasm can induce or aggravate cough
 Pulmonary receptor stimulation can induce both cough and
bronchoconstriction in individual with bronchial
hyperreactivity
 Relieve cough and clear secretions by increasing surface
velocity of airflow during cough
 Not used routinely
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29. Specific treatment approach to cough
Etiology of cough Treatment approach
Upper /lower respiratory tract
infection
Appropriate antibiotics
Smoking/chronic bronchitis Smoke cessation
Pulmonary tuberculosis Anti tubercular drugs
Asthmatic cough Inhalation of beta2 agonist,
ipratropium bromide
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30. References
Essentials of Medical Pharmacology,7th
editon, KD
Tripathi
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