Bronchial asthma pathophysiology & classification of drugs

Bronchial asthma patho-physiology and pharmacological drug classification

1. Bronchial asthma Pathophysiology and drug classification By: Dr chinmaya debasis panda

2. At a glance Introduction pathophysiology of bronchial asthma Classification of drugs

3. Introduction: Asthma is a chronic inflammatory disease of the airways that is characterized by : Activation of mast cells infiltration of eosinophils and T helper 2 (TH2) lymphocytes Usually accompanied by: Bronchial hyperactivity & bronchospasm Increased secretion Mucosal edema Mucus plug Characteristics: excessive narrowing of airways with caugh reduced airflow and symptomatic wheezing and dyspnea

4. Etiology: Genetic Developemental Environmental Inflamatory Imunological

5. Pathophysiology: Inflammation & Re-modelling of airways Hallmark: lymphocyte directed eosinophilic bronchitis Asthmatic diathesis(bronchial hyper-responsiveness) Clinically silent during basal state Mediators: Granules: histamine,heparin,tryptase,chymotrypsin,protease Membrane lipids: sulfidopeptide , leukotrienes , prostaglandins, PAF Cytokines: TNF α , leukotrienes (3,4,5,13)

6. S E N S I T I S A T I O N

7. Steps: Antigen/allergens exposure(house dust, mites, fur, pollens, rodents ) Cross-linking of IgE on mast cell surface(sensitization) Activation and degranulation of mast cells

8. Release of mediators Immediate bronchial reactions (Early reaction) Bronchospasm, local vasodilatation, increased capillary permeability, edema, chemotaxis (Rapid onset, peaks in 15-30 minutes, recovery in 24 hrs )

9. Release of inflammatory mediators by newly arrived cells Aggravation of airways inflammation & sustained bronchoconstriction (late phase reaction) (bronchoconstriction begins in 4-6hrs & lasts up to 24 hrs ) Bronchial hyper rensponsivenes may last up to 2 wks Incomplete recovery & repair - remodeling & persistent obstruction of airways (chronic asthma)

10. An attack of bronchial asthma may also be triggered by Viral infections Cold air Exercise Drugs Chemicals Histamine etc

11. Drug classification: I. Bronchodilators Selective β 2 adrenergic receptor agonists: Short acting: albuterol (salbutamol), levalbuterol , metaproterenol , terbutaline , fenoterol , tulobuterol , rimiterol , and pirbuterol . Long acting: Salmeterol , Formoterol 2. Non selective β 2 adrenergic receptor agonists : Orciprenaline , Adrenaline, Ephedrine

12. 3. Phosphodiesterase inhibitors: Theophylline (anhydrous), Aminophylline, Choline theophyllinate , Hydroxyethyl theophylline, Theophylline ethanolate of piperazine , Doxophylline 4. Anticholinergics : Ipratropium bromide, Tiotropium bromide .

13. II. Anti-inflammatory drugs : corticosteroids: A. Systemic: Hydrocortisone, Prednisolone and others. B. Inhalational: Beclomethasone dipropionate , Budesonide, Fluticasone propionate, Flunisolide , Ciclesonide . 2. Leukotriene modifiers: LT antagonist: Montelukast , Zafirlukast LT synthesis inhibitors: Z ileuton

14. 3. Mast cell stabilizers: Sodium cromoglycate , Nedocromil , Ketotifen . III. Anti- IgE antibody Omalizumab

15. THANK YOU By: Dr Chinmaya Debasis Panda m edtalksindia.blogspot.in