5.2 drugs used on bronchial asthma
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1. The document discusses drugs used to treat bronchial asthma, classifying them into bronchodilators, leukotriene antagonists, mast cell stabilizers, corticosteroids, and anti-IgE antibody. 2. Bronchodilators include selective beta-2 agonists like salbutamol and terbutaline, methylxanthines like theophylline, and anticholinergics. They work by relaxing airway smooth muscle. 3. Corticosteroids such as inhaled beclomethasone and budesonide reduce inflammation and the need for bronchodilator use. Systemic corticosteroids are used for severe or acute cases.
5.2 drugs used on bronchial asthma
- 1. DRUGS USED IN BRONCHIAL ASTHMA DR. SAROJ K. SUWAL
- 2. BRONCHIAL ASTHMA Asthma ( difficulty in Breathing) increased secretion, mucosal edema and mucus plugging. narrowing of air tubes, hyperresponsiveness of tracheobronchial smooth muscle Various Stimuli's
- 3. • Two types • Acute Asthma • Chronic asthma • status asthmatics( acute severe asthma) • Symptoms include • dyspnea, • wheezing, • cough and • may be limitation of activity. 3
- 4. CLASSIFICATION OF DRUGS FOR ASTHMA : 1. Bronchodilators A. sympathomimetics or β2 Agonist: • Salbutamol,Terbutaline, Bambuterol, Salmeterol, Formoterol, Ephedrine. • Non selective → adernaline B. Methylxanthines: • Theophylline , Aminophylline, Doxophylline. C.Anticholinergics: • Ipratropium bromide, Tiotropium bromide.
- 5. 2. Leukotriene antagonists: Montelukast, Zafirlukast. 3. Mast cell stabilizers: Sodium cromoglycate, Ketotifen. 4. Corticosteroids 1. Systemic: Hydrocortisone, Prednisolone and others. 2. Inhalational: Beclomethasone dipropionate, Budesonide, Fluticasone propionate, Flunisolide, Ciclesonide. 5.Anti-IgE antibody: Omalizumab
- 7. BRONCHODILATOR • Adrenaline • Non selective sympathomimetic • Produce a prompt and powerful bronchodilation bye acting through b2 adergenic receptor • useful in acute attack of asthma • given subcutaneously (0.2-0.5 ,; pf 1:1000 solution ) • used decreased because of dangerous effect on cardiac 7
- 8. SELECTIVE B2 AGONIST • first line drug for bronchial asthma • well tolerated in inhalational • At high dose may cause tremors, tachycardia, palpitation and rarely cardiac arrythmias • Eg. • Salbutamol, terbutaline
- 9. B2- SYMPATHOMIMETICS MOA • β2 receptor stimulation → increased cAMP formation in bronchial muscle cell → relaxation. • Increased cAMP in mast cells and other inflammatory cells decreases mediator release.
- 10. SALBUTAMOL • Selective short acting β2 agonist • Dose • Salbutamol 100-200mg inhalational every 6 hrs or as when required ( metered dose inhaler to terminate the attack • Other route→ IM, IV, Oral • Inhaled salbutamol produces bronchodilatation within 5 min and the action lasts for 2–4 hours. • It is, therefore, used to abort and terminate attacks of asthma, but is not suitable for round the- clock prophylaxis.
- 11. SALBUTAMOL CONTD………. • Uses • Used to terminate asthmatic attack • Respiratory solution is used in emergency • ADR • Muscle tremor, Palpitation, restlessness, nervousness, throat irritation and ankle edema. • Dose • 2-4mg oral • 200 microgram rotacps • 100 microgram MDI (metered dose inhaler)
- 12. TERBUTALINE • Effects, uses and action are similar to that of Salbutamol • Dose • Oral 2.5 mg • Inhalation 250 mcg
- 13. SALMETEROL AND FORMOTEROL • long-acting selective β2 agonists • Slow onset of action( salmeterol) • long onset of action ( formoterol) • Used by inhalation on a twice daily schedule for maintenance therapy and for nocturnal asthma, but not for acute symptoms. • Dose • Salmeterol 50 mcg BD • Formoterol 12 -24 mcg BD
- 14. METHYLXANTHINES • Naturally occurring alkaloids caffeine, theophylline and theobromine • Decreased used due to narrow margin of safety • are 3rd or 4th line drugs used for the asthma • Eg. theophylline
- 15. MECHANISM OF ACTION Blockade of adenosine receptors: • adenosine acts as a local mediator in CNS, CVS and other organs— contracts smooth muscles, especially bronchial; dilates cerebral blood vessels, depresses cardiac pacemaker. 15
- 16. THEOPHYLLINE • Mehthyl xanthine derivative • Potent bronchodilator than caffeine • well absorbed orally • MOA • inhibit phosphdiesterease→ casue bronchodilation • block adenosine receptor • anti inflammatory action • inscrease endogenous catecholamine relase • interfere with ca+ channel operaton Actions • Dilate smooth muscle of bronchus • Inhibit cardiac pacemaker • Enhance acid secretion • Inhibit histamine release
- 17. CLINICAL USE AND ADR Clinical uses • asthma maintenance treatment • COPD • Central sleep apnea Adverse effects • Narrow margin of safety • sudden death due to cardiac arrythmias • Dyspepsia, nausea, restlessness, flushing, hypotension, delirium, convulsion, shock, death. 17
- 18. ANTI CHOLINERGIC • Muscarnicien antagonist • M1,M2, M3 receptors subtypes in airway • selectively blocking M1,M3 result in bronchodilating effect • Ipratropium bromide • it binds to M-R subtypes(M1,M2 and M3) → inhibit Ach medical bronchospasm • selectively block effect of acetylcholine in bronchial smooth muscle • has slow onset of action • so , used in COPD and bronchaial asthma (chronic cases) 18
- 19. 2. LEUKOTRIENE ANTAGONIST • Anti leukotriene agents or drugs for Bronchodilatation, • common drugs →Montelukast and Zafirlukast • MOA • inhibit cysteinyl leukotriene → inhibit bronchoconstriction , decrease bronchial reactivity, decrease mucosal edema, decrease mucus hypersecretion • so, • reduced sputum eosinophil count, • suppression of bronchial inflammation and • hyperreactivity are suppressed with leukotriene antagonists.
- 20. • very safe drugs; • produce few side effects like headache and rashes. • Eosinophilia and neuropathy are infrequent. • Montelukast 10 mg OD, • Zafirlukast 20 mg BD Montelukast and zafirlukast are indicated for prophylactic therapy of mild-to- moderate asthma
- 21. MAST CELL STABILIZERS • are not bronchodilators • inhibit release of various mediators • histamine, LTs, PGs, etch by stabilizing the msat cell membrane • also reduce bronchial hyper reactivety • AG:AG reaction • Uses • allergic asthma • allergice congjuntiitis, • rallergice rhinitic, allergice dermatitis • Sodium cromoglycate • Inhibits degranulation of mast cells (as well as other inflammatory cells) by trigger stimuli. • Release of mediators of asthma like histamine, LTs, interleukins, etc. is restricted. • The basis of this effect is not well understood, but may involve Cl ion mediated cell stabilization,
- 22. • Bronchospasm, throat irritation and cough occurs in some patients. • Rarely nasal congestion headache, dizziness, arthralgia, rashes and dysuria have been reported. • 1- 5 mg inhaled dose • 2% soln used as decongestant spray
- 23. CORTICOSTEROIDS( GLUCOCORTICOIDS) MOA • inhibit phospholipase → prevent formation of various mediators ( TXA2, PG, ..leukotrines • are not direct bronchodilation effect • have effect like b2 agonist • Systemic and inhalational steriods • THEY • suppress inflammatory response ot AB-AG reaction • decrease mucosal edema • reduce bronchial hyperactivity
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- 25. INHALED STEROID • Beclomethasone dipropionate, Budesonide and Fluticasone have similar properties • MOA • suppress bronchial inflammation, • increase peak expiratory flow rate, • reduce need for β2-agonist inhalations and prevent episodes of acute asthma. • they have no role during an acute attack or in status asthmaticus 25
- 26. USE OF GLUCOCORTICOSTEROIDS Systemic glucocorticoids • used in acute sever asthmatics, chronic severe asthma • Hydrocortisone, Prednisolone , methylprednisolone
- 27. SYSTEMIC STEROIDTHERAPY Use systemic therapy only in following cases 1. Severe chronic asthma: • If not controlled by bronchodilators and inhaled steroids, • when there are frequent recurrences of increasing severity; • start with prednisolone 20–60 mg (or equivalent) daily; • attempt dose reduction after 1–2 weeks of good control and • finally try shifting the patient onto an inhaled steroid.
- 28. 2. STATUS ASTHMATICUS/ACUTE ASTHMA EXACERBATION: • Asthma attack not responding to intensive bronchodilator therapy start with high dose of a rapidly acting i.v. glucocorticoid which generally acts in 6–24 hour→shift to oral therapy for 5–7 days →discontinue abruptly or taper rapidly.
- 29. TREATMENT CHOICE 1. Mild episodic Asthma : less then one attack per day 1. Inhaled short acting B2 agonist during onset of attack 2. Seasonal Asthma 1. Regular inhaled sod. Cromoglycate or inhaled corticosteroid 200-400mcg per day, before 4 weeks and after 4 weeks of the season. 3. Mild chronic asthma 1. Regular inhaled steroids 200-400 mcg per day 2. Use short acting B2 agonists in episodes
- 30. 4. Moderate chronic asthma: more than one attack per day 5. Inhaled steroids 800 mcg per day 6. Inhaled long acting B2 agonist OD 5. Severe asthma : frequent attacks, continuous exacerbation 5. Inhaled steroids up to 2000 mcg per day 6. Inhaled long acting B2 agonists BD 7. Oral B2 agonist or leukotriene antagonist or theophylline OD 8. Treat episodes with short acting B2 agonists. 9. If not controlled yet, start oral steroids
- 31. Status asthmaticus/Refractory asthma • Any patient of asthma has the potential to develop acute severe asthma which may be lifethreatening. (i) Hydrocortisone 100 mg (or equivalent dose of another glucocorticoid) i.v. stat, followed by 100–200 mg 4–8 hourly infusion; (ii) Nebulized salbutamol (2.5–5 mg) + ipratropium bromide (0.5 mg) intermittent inhalations driven by O2. (iii) High flow humidified oxygen inhalation. (iv) Salbutamol/terbutaline 0.4 mg i.m./s.c. (v) Intubation and mechanical ventilation, if needed. (vi) Treat chest infection with intensive antibiotic therapy. (vii) Correct dehydration and acidosis with saline + sod. bicarbonate/lactate infusion
- 32. THANKS32