Drugs used for cough
- 1. Pharmacotherapy of Cough By Dr. Manoj Kumar Assistant Professor Department of Pharmacology Adesh Medical College & Hospital Ambala Can’t
- 2. Cough is a useful protective reflex that clears the respiratory tract of the accumulated mucus and foreign substances. It occurs due to stimulation of mechano / chemo receptors in throat, respiratory passage or stretch receptors in the lung.
- 4. Most common causes of cough • Common cold • Upper/lower respiratory tract infection • Allergic rhinitis • Smoking • Chronic bronchitis • Pulmonary tuberculosis • Asthma • Gastroesophageal reflux • Pneumonia • Congestive heart failure • Bronchiectasis • Use of drugs (e.g. ACEI), glucocorticoids, iodine
- 5. COUGH Non Productive (Dry) Types of cough Cough is 2 types Productive (Tenacious)
- 6. Non productive:- • No useful purpose. • It increased discomfort to the patient. • Treatment Antitussive agents are useful. Productive cough:- • It is characterized by presence of excessive sputum and may be associated with conditions such as chronic bronchitis and bronchiectasis. • In this condition expectorants are useful.
- 7. • Antitussive suppress the frequency as well as intensity of coughing without affecting the normal elimination of excessive secretions from the respiratory tract. • Expectorants Increase the volume and decrease the viscosity of secretions to enhance the force of the secretion upward and outward by ciliary movement and coughing.
- 8. Peripherally acting Centrally acting Peripherally & centrally Pharyngeal demulcents Expectorants Opioids Non Opioids Mucokinetics Mucolytic Benzonatate Classification of drugs
- 9. Peripherally acting Pharyngeal demulcents Lozenges Cough drops Linctuses containing syrup Glycerine Liquorice Expectorants:- 1.Mucokinetics – Ammonium chloride – Sodium citrate – Potassium Iodide – Guaifenesin – Ipecacuanha 2.Mucolytic – Vasaka – Bromhexine – Ambroxal – Dornase alfa – Acetyl cysteine
- 10. Centrally and peripherally acting • Opioids Centrally acting • Non Opioids – Codeine – Pholcodeine – Morphine – Ethylmorphine – Noscapine – Dexomethorphan – Pipazethate – Chlophedinol – Oxeladin • Benzonatate
- 11. 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
- 12. Drugs for cough Cough can be treated : By Nonspecific therapy With specific remedies(antibiotics,etc)
- 13. Demulcents and expectorants Pharyngeal demulcents Coat the pharynx and produce Sooth effect in throat. Increase flow of saliva from P. mucosa. Reduce afferent impulses from the inflamed/irritated Mucosa Action less then – 30 mints. Useful for the symptomatic relief in dry cough arising from throat
- 14. Expectorant Two category: Bronchial secretion enhancer Mukolytics Demulcents and expectorants cont…
- 15. Expectorants Mucokinetics • Bromhexine derivative of alkaloid vasicine obtained from Adhatoda vasica. • Potent mucolytic and mucokinetic, capable of inducing thin copious bronchial secretion. • It is particularly useful if mucus plugs are present. • Side effects:- rhinorrhoea and lacrimation, nausea, gastric irritation, hypersensitivity. • Dose:- adults 8 mg TDS, children 1–5 years 4 mg BD,
- 16. Expectorants cont… Ambroxol: A metabolite of bromhexine Mucolytic action, uses and side effects similar to bromhexine Dose: 15-30 mg TDS Acetylcysteine Derivative of cysteine Opens disulfide bonds on mucoproteins present in sputum Also act as antioxidants Reduce airway inflammation
- 17. Expectorants cont… Carbocysteine: Liquefies viscid sputum Administered orally (250-750 mg TDS) May be break gastric mucosal barrier Contraindicated in peptic ulcer Side effects: Gastric discomfort and skin rashes
- 18. Demulcents and expectorants cont… Bronchial secretion enhancer Sodium or Potassium citrate saltaction Potassium iodide Secreted by bronchial glands Irritate airways mucosa Prolonged use Disturb thyroid function Iodism Not used now
- 19. Demulcents and expectorants cont… 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
- 20. 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 disturbs sleep /hazardous
- 21. Antitussives (cont..) Ophoids: Codeine Opium alkaloid Less potent than morphine more selective for cough center Standard antitussive: suppress cough for 6 hours Side effects: At higher doses respiratory depression especially in children Constipation is main drawback, Driving may be impaired Contraindicated in asthmatics and patients with diminished respiratory reserve Avoided in children. Abuse Dose: 10–30 mg; children 2–6 years 2.5–5 mg, 6–12 years 5–10 mg
- 22. Antitussives (cont..) Ophoids: Ethylmorphine Closely related to codeine 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.
- 23. 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
- 24. Antitussives (cont..) Nonopioids: Dextromethorphan A synthetic central NMDA 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.
- 25. Antitussives (cont..) Nonopioids: Chlophedianol A centrally acting antitussive Slow onset and longer duration of action. Dose: 20–40 mg Side effect Dryness of mouth Vertigo Irritability
- 26. Antitussives (cont..) 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
- 27. Antitussives (cont..) Antihistamines: H1 blockers are added to antitussive/expectorants Relief in cough due to their sedative and anticholinergic action Lack selectivity for cough center Have no expectorant property
- 28. Antitussives (cont..) 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
- 29. 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
- 30. Specific treatment approach to cough Etiology of cough Upper/lower respiratory tract infection Smoking/chronic bronchitis/bronchiectasis Pulmonary tuberculosis Asthmatic cough Gastro esophageal reflux ACE inhibitor associated cough Postnasal drip due to sinusitis Treatment approach Appropriate antibiotics Cessation of smoking/avoidance of pollutants, steam inhalation Anti tubercular drugs Inhaled β2 agonists/corticosteroids/ipratropium Light dinner, diet modification, H2 blocker, PPI Losartan. Antibiotic, nasal decongestant, H1 antihistaminic
- 31. Wrong preacher for cough syrup administration
- 32. Thank You