Asthma 2024-2025 PDF

Adliah Mhd Ali Faculty of Pharmacy UKM NFNF3613  Learning Outcomes  At the end of the lecture, you should be able to:  Understand the etiology and pathogenesis of asthma.  Understand the clinical presentation and factors triggering asthma.  Understand the assessment/...

Adliah Mhd Ali Faculty of Pharmacy UKM NFNF3613  Learning Outcomes  At the end of the lecture, you should be able to:  Understand the etiology and pathogenesis of asthma.  Understand the clinical presentation and factors triggering asthma.  Understand the assessment/monitoring involved in asthma.  Understand asthma classification based on the severity.  Understand the goal of treatment in asthma management.  Understand the general and specific management involved in asthma. NFNF3613 Definition and Clinical Presentation  is a chronic inflammation disorder of the airways which leads to the recurrent symptoms of:  Wheezing.  Breathlessness.  Chest tightness.  Cough particularly at night, early morning or associated with exercise. NFNF3613 NFNF3613  Involves inflammation of the pulmonary airways and bronchial hyperresponsiveness --→ lower airway obstruction (reversible).  Triggering factors:  cold air.  exercise, viral upper respiratory infection, cigarette smoke, and respiratory allergens.  Bronchial provocation with allergen induces a prompt early phase immunoglobulin E (IgE)- followed by a late- phase IgE mediated reaction. NFNF3613 Etiology and Pathogenesis NFNF3613  Pulmonary Function Tests (PFTs)  Spirometry:  Measures lung volumes and airflow dynamics.  FEV1 : 75% of a predicted normal of 4L (Normal).  FVC: 75% of a predicted normal of 3.2L (Normal).  Measurement: FEV1/FVC.  Peak Expiratory Flow Rate (PEFR)  Maximal flow rate that can be produced during forced expiration following a deep breath to full inspiration.  Normal: 550-700 L/min (adult). NFNF3613 NFNF3613 Peak Flow Meter Indicators NFNF3613 NFNF3613 NFNF3613  Goals of Asthma Management (GINA 2024)  Achieve best possible long term outcomes for the individual patient.  Good long term symptom control (few/no asthma symptoms, no sleep disturbance due to asthma, unimpaired physical activity).  Minimized long term risk of asthma related mortality, exacerbations, persistent airflow limitation and side effects of treatment.  Identify patient own goals. NFNF3613  Patient and Family Education  Patient education should include :  Nature of asthma.  Preventive measures/avoidance of triggers.  Drugs used and their side-effects.  Proper use of inhaled drugs.  Proper use of peak flow meter.  Knowledge: the difference between relieving and preventive medications.  Recognition of features of worsening asthma (increase in bronchodilator requirement, development of nocturnal symptoms, reducing peak flow rates).  Self management plan for selected, motivated patients or parents.  The danger of non prescribed self medication including certain traditional medicines. NFNF3613 Avoidance of Precipitating Factors  Beta blockers - contraindicated in all asthmatics.  Aspirin and nonsteroidal anti-inflammatory drugs - if known to precipitate asthma, these drugs should be avoided.  Allergens, e.g. house dust mites, domestic pets, pollen should be avoided whenever possible.  Occupation - should be considered as a possible precipitating factor.  Smoking - active or passive.  Day to day triggers - such as exercise and cold air.  Atmospheric pollution.  Food - if known to trigger asthma, should be avoided. NFNF3613  Drug Treatment  2 major groups of drugs to treat asthma:  Bronchodilator drugs - to relieve bronchospasm and improve symptoms.  Anti inflammatory drugs - to treat the airway inflammation and bronchial hyperresponsiveness, the underlying cause of asthma e.g to prevent attacks. NFNF3613  Bronchodilators  These drugs treat symptoms of asthma.  Should be used as required rather than regularly. When asthma is severe and difficult to control, bronchodilators may be taken on regular basis. There are 3 main groups of bronchodilators: a. Beta2 agonists. b. Anticholinergics. c. Methylxanthines. NFNF3613  Beta2 Agonists  The most effective bronchodilators.  Action: smooth muscle relaxation, mast cell membrane stabilisation, skeletal muscle stimulation.  Safe drugs with few side effects when taken by inhalation.  Therapeutic effect : within a few minutes of inhalation.  Main side effects : tremors and tachycardia.  Oral slow release preparations and inhaled long acting beta2 agonists such as Salmeterol are useful for nocturnal asthma. Examples: Inhaled beta2 agonist: salbutamol (Ventolin, Respolin) terbutaline (Bricanyl) fenoterol (Berotec) salmeterol (Serevent) - long acting Oral short acting beta2 agonist: salbutamol terbutaline NFNF3613  Anticholinergic Drugs  Inhaled anticholinergics: lower onset but longer duration of action.  Very few side effects: Ipratropium bromide (Atrovent). NFNF3613  Methylxanthines  Available in oral and parenteral forms.  Their usefulness is limited by variable metabolism and a narrow therapeutic window.  Sustained release preparations: useful in nocturnal Sx Example: Nuelin SR. NFNF3613  Anti-Inflammatory Drug  Corticosteroids  Main prophylactic drugs in adult asthmatics.  Mechanism: Anti-inflammatory and mast cell stabilisation properties that decrease airway hyperresponsiveness.  Should be taken by inhalation and the dosage should be kept to a minimum to reduce side effects (usually local side effects).  Oral steroids : severe chronic asthma. Examples: Beclomethasone dipropionate (Becotide,Becloforte) Budesonide (Pulmicort). NFNF3613 NFNF3613 Malaysian Thoracic Society Guideline NFNF3613 Management of Poor Control of Asthma (GINA 2024) NFNF3613 NFNF3613 NFNF3613