TREATMENT OF COUGH

1. TREATMENT OF COUGH

2. TREATMENT OF COUGH • Cough is a useful physiological mechanism that serves to clear the respiratory passages of foreign material and excess secretions. • It should not be suppressed تكبت - تمنع indiscriminately. • There are, however, many situations in which cough does not serve any useful purpose but may, instead only annoy the patient or prevent rest and sleep.

3. TREATMENT OF COUGH • Chronic cough can contribute يساهم في to fatigue, especially in elderly patients, in such situations the physicians should use a drug that will reduce the frequency or intensity شده of the coughing. • Cough reflex اقرا الفيسيو للشرح is complex, involving the central and peripheral nervous systems as well as the smooth muscle of the bronchial tree.

4. TREATMENT OF COUGH • It has been suggested that irritation of the bronchial mucosa causes bronchoconstriction, which in turn, stimulates cough receptors( which probably represent a specialized type of stretch receptor) located in the tracheobronchial passages.

5. TREATMENT OF COUGH • Afferent ناقل للاشاره نحو المركز ( المخ او الحبل الشكوكي ) مهمه conduction from these receptors is via fibers in the vagus nerve; central components of the reflex probably involve several mechanisms or centres that are distinct تختلف عن from the mechanisms involved in the regulation of respiration.

6. TREATMENT OF COUGH • The drugs that directly or indirectly can affect this complex mechanism are diverse متنوع. • مهمهFor example , cough may be the first or only symptom in bronchial asthma or allergy, and in such cases bronchodilators(e.g., 2 – adrenergic receptor agonists have been shown to reduce cough without having any significant central effects, other drugs act primarily on the central or the peripheral nervous system components of the cough reflex.

7. COUGH Forceful release of air from lungs Sudden, often involuntary (protective) reflex and major defensive mechanism وسيله دفاعيه للجسم Cont…..

8. Causes of cough : • Expulsion طرد - اخراج of respiratory secretion or foreign particles or irritant or excessive mucus from air passages • Symptom عرض لمرض قلبي او رئوي of an underlying respiratory and/or cardiovascular pathology مهمه • السبب الاخير : اذا بتنبه واحد تكح عشان ينتبه ( اهم وحده )

9. Mechanism of cough Stimulation of mechano-or chemoreceptors(throat, respiratory passages or stretch receptors in lungs) Afferent impulses to cough centre (medulla) Efferent impulses via parasympathetic & motor nerves to diaphragm, intercostal muscles & lung Increased contraction of diaghramatic, abdominal & intercostal (ribs) muscles noisy expiration (cough)

10. Cough Reflex اماكن وجودها : 1-على امتداد القناة التنفسيه 2-في المعده 3- في الجيوب الانفيه

11. Types of cough • Acute cough =lasting<3 weeks • Chronic cough =lasing >8 weeks Cough may be i) Un productive (dry) cough OR ii) Productive cough (sputum) cont.

12. 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., Angiotensin-converting enzyme inhibitors) الدكتور ركز عليها

13. Treatment of Cough 1) Antitussives (cough centre suppressants) ادويه تقوم بحظر مركز السعال في المخ 2) Expectorants الطارد للبغلم بواسطه تحويله لماده اخف مما هو عليه فيخرج بسهوله (Mucokinetics) 3) Mucolytics المحلل للبلغم : نفس فكره رقم 2 4) Antihistamines 5) Bronchodilators 6) Pharyngeal Demulcents الملين

14. 1) Antitussives (cough centre suppressants) Drugs suppress cough & produces symptomatic relief تعافي من الاعراض MOA Mainly suppress cough centre in medulla (both central & peripheral effects) E.g., Opoid drugs (codeine, pholcodeine, noscapine, dextromethorphan) Opioid = most effective for cough

15. i) Codeine • Codeine= prodrug  metabolized to morphine • It is an alkaloid ماده قاعديه found in Opium poppy plant • Has less addiction ادمان اقل من المورفين+ • resp. centre depressant ↓ • Has useful antitussive المضاد للسعال action at low doses (<15 mg) • Produce drowsiness, thickening of sputum & constipation

16. ii) Noscapine & Pholcodeine • Related to papaverine البابافارين : دواء مريح للعضلات • Do not have addictive ادماني, analgesic مسكني & constipating امساكي properties • Do not interfere يتعارض مع with mucocilliary movement • Noscapine (15 mg) & pholcodeine (10 mg)=syrup شراب

17. iii) Dextromethorphan Available in syrup, tablets, spray forms MOA NMDA receptor antagonist Uses Cough suppressant, temporary relief of cough caused by minor throat & bronchial irritation (accompanies with flu & cold), pain relief Ad Effects= Nausea, vomiting, drowsiness, dizziness, blurred vision

18. 2) Expectorants (Mucokinetics) • Act peripherally يعني بعيدا عن المخ • Increase bronchial secretion OR • Decrease its viscosity  facilitates its removal by coughing • Loose cough ►less tiring حدّه & more productive Cont….

19. Classification of Expectorants Classified into b) Directly acting E.g., Guaifenesin (glyceryl guaiacolate), Na+ & K+ citrate or acetate, b) Reflexly acting E.g., Ammonium salt

20. i) Sodium & potassium citrate or Acetate • They act directly Actions: ▲Bronchial secretion by salt action ii) Guaifenesin • Expectorant طارد للبلغم drug usually taken by mouth • Available as single & also in combination MOA=Increase the volume & reduce the viscosity of secretion in trachea & bronchi

21. iii) Reflexly acting يعني تؤثر على المعده مما يؤدي لاثر عكسي وهو زياده السيكريشن في القصبات االهوائيه وايضا زياده التعرق Ammonium salts Gastric irritants reflexly  bronchial secretions + sweating

22. 3) Mucolytics Help in expectoration طرد البلغم by liquefy التحويل لشكل ذو سيوله اكثر the viscous tracheobronchial secretions E.g., Bromhexine, Acetyl cysteine, i) Bromhexine Synthetic derivative of vasicine(alkaloid= Adhatoda vasica) Cont….

23. MOA of Bromhexine a) Thinning & fragmentation of mucopolysaccaride fibers b) ↑ volume & ↓ viscosity of sputum ii) Acetylcysteine Given directly into respiratory tract cont.

24. MOA of acetylcysteine Opens disulfide bond رابطه في بروتين البلغمin mucoproteins of sputum =↓ viscosity Uses Cystic fibrosis (to viscosity of sputum) Onset of action quick---used 2-8 hourly Adverse effects Nausea, vomiting, bronchospasm in bronchial asthma

25. 4) Antihistamines • Added to antitussives/expectorant formulation • Due to sedative الاثر المهدئ & anticholinergic actions produce relief in cough but lack selectivity for cough centre • No expectorant action =▼secretions (anticholinergic effect) • Suitable for allergic cough (not for asthma) E.g., Chlorpheniramine, diphenhydramine, promethazine

26. 5) Bronchodilators • Bronchospasm or stimulation of pulmonary receptors = induce or aggravate زيادهcough + bronchoconstriction • e.g. β2-agonist (salbutamol, terbutaline) MOA of bronchodilators in cough • ▲surface velocity of air flow during cough→ Clear secretions of airway • مهمهNot used routinely for every type of cough but only when bronchoconstriction is present

27. 6) Pharyngeal demulcents مطري • Soothe يهدئ the throat (directly & also by promoting تحفيز salivation اللعاب) • ▼ afferent impulses from inflamed/irritated pharyngeal mucosa • Provide symptomatic relief in dry cough arising from throat E.g. lozenges, cough drops, glycerine, liquorice, honey العسل ( طب شعبي )

28. Specific treatment approach to cough Etiology of coughTreatment 1) Upper/lower respiratory Appropriate antibiotics tract infections 2) Smoking/chronic bronchitis Cessation of smoking 3) Pulmonary tuberculosis Antibiotics 4) Asthmatic cough Inhaled β2-agonists/iprat- ropium/corticosteroid 5) Postnasal drip (sinusitis) Antibiotics, nasal decon- gestants, antihistamines