Drugs used in respiratory disorders

This presentation was used for lecture class of BSc Nursing First year students.

1. Drugs used in Respiratory Disorders Dr. Pravin Prasad M.B.B.S., MD Clinical Pharmacology Lecturer, Lumbini Medical College 7 March, 2019 (23 Falgun 2075), Thursday

2. By the end of the class BSN 1 st year students will be able to: Classify drugs used in the treatment of: Cough Bronchial Asthma Classify antihistamines Explain the mechanism of action, indications and adverse effects of: Salbutamol Cetirizine

3. Cough: Introduction Is a protective reflex Types: Productive (Useful) Sputum produced Drains the respiratory tract Non-productive (Useless) Needs to be supressed if tiring

4. Drugs used for cough: Classification Pharyngeal demulcents Used for cough due to pharyngeal irritation Lozenges, cough drops, linctus containing syrup Expectorants ( Mucokinetics ) Helps to cough out bronchial secretions and clear airway Bronchial secretion enhancers: Guaiphenesin, Ammonium chloride Mucolytics: Bromhexine, Acetylcysteine, Carbocisteine

5. Drugs used for cough: Classification Antitussives Acts by suppressing cough centre or decreasing tussal impulses or both Opioids: Codeine, Pholcodine Nonopioids: Dextromethorphan Antihistamines: Chlorpheniramine, Diphenhydramine, Promethazine Adjuvant antitussives Bronchodilators: Salbutamol, Terbutaline

6. Drugs used for cough: Classification Adjuvant antitussives Useful in cough associated with bronchospasm or bronchoconstriction Bronchodilators: Salbutamol, Terbutaline

7. Drugs used in Bronchial asthma

8. Bronchial Asthma Is an primarily inflammatory condition Characterised by hyperresponsiveness of the respiratory tract to various stimuli Results into: Narrowing of bronchial tree, and Increased secretion, mucosal oedema and plugging Symptoms: dyspnoea, wheezing, cough and Limitation of activity

9. Drugs used in Bronchial asthma Bronchodilators β 2 Sympathomimetics: Salbutamol, Terbutaline Methylxanthines: Theophylline, Aminophylline, Doxophylline Anticholinergics: Ipratropium bromide, Tiotropium bromide Leukotriene antagonists: Montelukast, Zafirlukast Mast cell stabilizers: Sodium cromoglycate, Ketotifen Corticosteroids Systemic: Hydrocortisone, Prednisolone Inhalational: Beclomethasone, Budesonide, Fluticasone Anti- IgE antibody: Omalizumab

10. Salbutamol Highly selective for β 2 receptors Short acting: effect seen in 5 mins of inhalation Acts by stimulating β 2 receptors Increases cAMP and leads to Bronchial smooth muscle relaxation Reversible airway obstruction relived Administered by inhalation, sometimes oral/ injectable

11. Salbutamol: Uses Asthma Terminate attacks of asthma Chronic Obstructive Pulmonary Disease Mild cases (severe cases- long acting drugs) Acute exacerbation Cough When aggravated by bronchoconstriction Hyperkalaemia

12. Salbutamol: Adverse effects Hypokalaemia Muscle tremor Principle side effect Throat irritation When administered by inhalation route Palpitation, restlessness, nervousness Stimulation of β 1 receptors in heart Ankle oedema

13. Antihistamines

14. Antihistamines Binds to histamine receptors and blocks the activity of histamine H 1 antihistamines Conventional antihistamines H 2 antihistamines Used for decreasing gastric secretions H 3 antihistamines Unknown clinical uses

15. Conventional Antihistamines Acts by blocking H 1 receptors Categorised into two generations First generation Second generation Less sedating Higher H 1 selectivity Additional antiallergic mechanisms

16. Antihistamines: Classification First generation: Highly sedative Diphenhydramine, Promethazine Moderately sedative Cyproheptadine, Pheniramine Mild sedative Chlorpheniramine, Triprolidine Second generation: Fexofenadine Loratadine Desloratadine Levocetirizine Cetirizine Ebastine

17. Antihistamines: Uses Allergic disorders Itching, urticaria, seasonal hay fever, allergic conjunctivitis and angioedema of lips, eyelids Insect bite, Ivy poisoning Idiopathic pruritis Older antihistamines: Common cold, motion sickness, cough, Parkinsonism

18. Antihistamines: Adverse effects Mild sedation Somnolence

19. Any queries? Thank you.