TREATMENT OF COUGH

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 - تمنع تكبتindiscriminately.

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.

TREATMENT OF COUGH

Chronic cough can contribute في to يساهمfatigue, 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 للشرح الفيسيو ,is complex اقراinvolving the central and peripheral nervous systems as well as the smooth muscle of the bronchial tree.

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.

TREATMENT OF COUGH

Afferent ( الحبل او المخ المركز نحو لالشاره ناقلمهمه ( conduction from these الشكوكي

receptors is via fibers in the vagus nerve; central components of the reflex probably involve several mechanisms or centres that are distinct عن from the mechanisms تختلفinvolved in the regulation of respiration.

TREATMENT OF COUGH

The drugs that directly or indirectly can affect this complex mechanism are diverse متنوع.

For example , cough may be the first or onlyمهمه 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.

COUGH

Forceful release of air from lungs

Sudden, often involuntary (protective) reflex and major defensive mechanism وسيله

للجسم دفاعيهCont…..

Expulsion - اخراج of respiratory secretion or طردforeign particles or irritant or excessive mucus from air passages

Symptom رئوي او قلبي لمرض of an عرضunderlying respiratory and/or cardiovascular pathology مهمه

( : اهم ينتبه عشان تكح واحد بتنبه اذا االخير السببوحده (

Causes of cough :

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)

Cough Reflex

وجودها : اماكن

امتداد -1 علىالتنفسيه القناة

2- المعده فيالجيوب -3 في

االنفيه

Types of cough

A) Acute cough =lasting<3 weeks

B) Chronic cough =lasing >8 weeks

Cough may be

i) Un productive (dry) cough OR

ii) Productive cough (sputum)

cont.

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)

عليها ركز الدكتور

Treatment of Cough

1) Antitussives (cough centre suppressants) ادويهالمخ في السعال مركز بحظر تقوم

2) Expectorants لماده تحويله بواسطه للبغلم الطاردبسهوله فيخرج عليه هو مما (Mucokinetics) اخف

3) Mucolytics : رقم فكره نفس للبلغم 2المحلل4) Antihistamines

5) Bronchodilators

6) Pharyngeal Demulcents الملين

1) Antitussives (cough centre suppressants)

Drugs suppress cough & produces symptomatic relief االعراض من تعافي

MOA Mainly suppress cough centre in medulla (both central &

peripheral effects)

E.g., Opoid drugs (codeine, pholcodeine, noscapine, dextromethorphan)

Opioid = most effective for cough

i) Codeine

Codeine= prodrug metabolized to morphine It is an alkaloid قاعديه found in Opium poppy ماده

plant Has less addiction المورفين من اقل +ادمان resp. centre depressant ↓ Has useful antitussive للسعال المضادaction at low doses (<15 mg) Produce drowsiness,

thickening of sputum &

constipation

ii) Noscapine & Pholcodeine

Related to papaverine : مريح دواء البابافارينللعضالت

Do not have addictive ادماني, analgesic مسكني & constipating امساكي properties

Do not interfere مع with mucocilliary يتعارضmovement

Noscapine (15 mg) & pholcodeine (10 mg)=syrup شراب

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

2) Expectorants (Mucokinetics)

Act peripherally المخ عن بعيدا يعني Increase bronchial secretion OR Decrease its viscosity facilitates its removal by

coughing Loose cough ►less tiring هWدXXXح & more

productive

Cont….

Classification of Expectorants

Classified into b) Directly acting E.g., Guaifenesin (glyceryl guaiacolate), Na+

&

K+ citrate or acetate,

b) Reflexly actingE.g., Ammonium salt

i) Sodium & potassium citrate or Acetate

They act directlyActions: ▲Bronchial secretion by salt action

ii) Guaifenesin Expectorant للبلغم drug usually taken by طارد

mouth Available as single & also in combination

MOA=Increase the volume & reduce the viscosity of secretion in trachea & bronchi

iii) Reflexly acting على تؤثر يعنيوهو عكسي الثر يؤدي مما المعدهالقصبات في السيكريشن زياده

التعرق زياده وايضا االهوائيه

Ammonium saltsGastric irritants reflexly bronchial

secretions + sweating

3) Mucolytics

Help in expectoration البلغم by liquefy طرداكثر سيوله ذو لشكل the viscous التحويل

tracheobronchial secretionsE.g., Bromhexine, Acetyl cysteine,

i) BromhexineSynthetic derivative of vasicine (alkaloid= Adhatoda

vasica)Cont….

MOA of Bromhexinea) Thinning & fragmentation of

mucopolysaccaride fibersb) ↑ volume & ↓ viscosity of sputum

ii) AcetylcysteineGiven directly into respiratory tract cont.

MOA of acetylcysteine

Opens disulfide bond البلغم بروتين في in رابطهmucoproteins of sputum =↓ viscosity

UsesCystic fibrosis (to viscosity of sputum)Onset of action quick---used 2-8 hourlyAdverse effectsNausea, vomiting, bronchospasm in bronchial

asthma

4) Antihistamines

Added to antitussives/expectorant formulation Due to sedative المهدئ anticholinergic actions & االثر

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

5) Bronchodilators

Bronchospasm or stimulation of pulmonary receptors = induce or aggravate زياده cough + bronchoconstriction

e.g. β2-agonist (salbutamol, terbutaline)

MOA of bronchodilators in cough ▲surface velocity of air flow during cough→ Clear

secretions of airway Not used routinely for every type of cough butمهمه

only when bronchoconstriction is present

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 شعبي ) ( طب العسل

Specific treatment approach to cough

Etiology of cough Treatment

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