This document discusses drugs acting on the respiratory system. It begins by defining cough and its types. It then discusses common respiratory conditions like asthma and COPD in detail. The causes, symptoms and treatment options for cough, asthma and COPD are explained. Finally, it discusses various classes of drugs used for cough like expectorants, suppressants and adjuvents. Specific drugs like codeine, dextromethorphan, ammonium chloride, guaifenesin, bromhexine and bronchodilators are also explained in terms of their mechanisms, indications, doses and side effects.
2. COUGH
• Also known as tussis
• It is protective reflux which helps to expel irritant matter
from the respiratory system.
• A rapid expulsion of air from the lungs, typically in order
to clear the lung airways of fluids, mucus , or other
material. It occurs especially at night or in morning
• This is necessary for preventing mechanical
obstruction to breathing
• Frequent breathing indicates the presence of disease
• Many virus and bacteria benefit evolutionary by causing
the host to cough, which helps to spread disease to
new hosts
3. Types of cough
1. productive cough
• Also called wet cough
• It brings up mucus or other fluid, including blood
• It literally creates a gurgling obstruction sound when it occurs
2. Non-productive cough
• also known as a dry cough
• It is one that does not bring up any mucus or other secretions.
• It is caused by irritation in the throat, which many people
describe as a “scratchy” or “tickling” sensation.
4. CAUSES OF COUGH
• Enviromental cause i.e. dust smoke pollution etc
• Smoking cigarettes
• Common cold , lung infection, asthama, GERD
• Upper respiratory tract infection( URTI)
• Chronic pulmonary disease( bronchitis, tuberclosis, lung cancer
etc)
• Secondrary to acute left ventricular failure( Cardiac )
• Drug related: ACE inhibitor (..pril), Beta-blocker(..olol), inhaled
ether, inhaled corticosteroids, levodopa, nitrofurantine etc
5. ASTHMA
Some people refer to asthma as "bronchial asthma."
• Asthma is a long term inflammatory disease of the airways of
the lungs
• Asthma is a condition in which airways narrow and swell and
may produce extra mucus.
• This can make breathing difficult and trigger coughing, a
whistling sound (wheezing) when breathe out and shortness of
breath.
• Asthma can't be cured, but its symptoms can be controlled.
Because asthma often changes over time, adjust treatment as
needed.
6. There are three major signs of asthma(major factor of causes of
asthama)
• Airway blockage.
When breathe as usual, the bands of muscle around airways
are relaxed, and air moves freely. But when asthma, the muscles
tighten. It’s harder for air to pass through it.
• Inflammation.
Asthma causes red, swollen bronchial tubes in lungs. This can
damage lung. Treating this is key to managing asthma in long
run.
• Airway irritability.
People with asthma have sensitive airways that tend to
overreact and narrow when they come into contact with even
slight triggers.
7. CHRONIC OBSTRUCTIVE PULMONARY
DISEASE(COPD)
• COPD refers to chronic bronchitis and emphysema, a
pair of two commonly co-existing disease of the lung in
which the airways become narrowed
• This leads to a limitation of the flow of air and from the
lungs causing shortness of breath
• COPD is also known as chronic obstructive lung
disease (COLD), chronic obstructive airway disease
(COAD), chronic airflow limitation (CAL), and chronic
obstructive respiratory disease (CORD)
8. Signs and symptoms of COPD:
• shortness of breath (dyspnea).
• In the advanced stages of COPD, dyspnea can
become so bad that it occurs during rest
• Other persistent cough, sputum or mucus production,
wheezing, chest tightness , and tiredness
• very severe COPD : respiratory failure.
• An excess of carbon dioxide in the blood can cause
headaches, drowsiness or twitching.
• Other Common signs are:
- Tachypnea, a rapid breathing rate,
- Wheezing sounds or crackles in the lungs is heard
through a stethoscope
- Breathing out taking a longer time than breathing in
9. Causes of COPD
1. Smoking
• It develops often as a result of smoking, but also occur from
long term inhalation of irritants into the lungs dust , chemical
• long-term exposure to second hand smoke
2. Occupational exposures
• Intense and prolonged exposure to workplace dusts found in
coal mining, gold mining, and the cotton textile industry and
chemicals such as cadmium, isocyanates, and fumes from
3. Air pollution
• people who live in large cities have a higher rate of COPD
compared to people who live in rural areas
• Urban air pollution may be contributing factor for COPD
• indoor air pollution from cooking fire smoke
10. 4. Genetics
• Alpha 1 -antitrypsin deficiency is a genetic condition that is
responsible for about 2% of cases of COPD
• In this condition, the body does not make enough of a protein,
Alpha 1 –antitrypsin protects the lungs from damage caused by
protease enzymes, such as elastase and trypsin that can be
released as a result of an inflammatory response to tobacco
smoke
11. Classification of drug for cough
1. Pharyngeal demulcent: Menthol, thymol, eucalyptus
2. Cough expectorants:
a. Bronchial secretion enhancer: Sod/pot. Citrate, pot. Iodide,
ammonium chloride, guaifenesin
b. Mucolytics: bromohexine, ambroxol, acetylcysteine,
3. Cough suppressants(anti-tussive) :-
a. Opioids : codeine, pholcodeine
b. Non-opioids : noscapine, dextromethorphan
c. Antihistamine: promethazine, chlorpheniramine
4 Adjuvents anti-tussive: salbutamol , terbutaline
12. Codeine
• It is an opioid central acting anti-tussive drug.
• It is pro-drug of morphine used to treat pain, coughing, and
diarrhea and is commonly abused
• It is found naturally from opium poppy, Papaver somniferum
Mechanism of action:
Codeine mimics the actions of endogenous opioids by binding to
the mu-opioid receptors
Indication:
pain, coughing and diarrhea
14. Dextromethorphan
• It is often referred to as DXM or DM, is a medication most often
used as a cough suppressant
• It is in the morphinan class of medications with sedative,
dissociative and stimulant properties
Mechanism of action:
• It reduce cough reflex by direct action on the cough center in the
brain medulla.
• It is glutamate receptor antagonist and sigma 1,2 opioid
receptor agonist
15. Indication:
• used as a cold and cough medicine
• With other combination used for neurological and
neuropsychiatric disorder
Side effect:
GI disturbance, dizziness, restlessness nerviousness,
hallucination etc.
Contraindication:
Respiratory failure, who use antidepressant (MAOI’s) drug,
asthma and renal failure
Dose: Adult: 20mg every 4 hour
child: 2-6 yr: 5mg every 4hr, 6-12 yr: 5-10mg every 4hr
16. AMMONIUM CHLORIDE
Ammonium chloride is an inorganic compound with the formula
NH4CI.
Uses and action:
• as an cough expectorant
• It’s expectorant action is caused by irritative action on the
bronchial mucosa which causes the production of excess
respiratory tract fluid which presumably is easier to cough up
• Ammonium chloride injection , after dilution in isotonic sodium
chloride injection, may be indicated in the treatment of patients
with hypochloremic states and metabolic alkalosis
17. Contraindication:
• severe impairment of renal or hepatic function
• pregnant women
Side effects:
• May occasionally produce gastrointestinal discomfort, nausea
and vomiting
Dose:
• Adults and children over 12 years: 10ml daily.
• Children under 12 years: Not recommended.
18. BROMHEXINE
• Bromhexine is a synthetic derivative of the herbal active
ingredient vasicine
• It is a mucolytic or expectorant agent used in the treatment of
respiratory disorders associated with viscid or excessive mucus
Mechanism of action:
• It exerts its action as mucolytic by depolymerizing mucus
polysaccharides both by a direct action and through release of
lysosomal enzymes, thus liquefying the mucous plug of sputum
19. Indication:
• respiratory tract disorders, mostly in dry and productive cough
• dry eye syndrome
Contraindication and Precautions:
- Hypersensitivity -peptic ulceration and asthma
Side effects:
- Headache -Dizziness
- Lacrimation - GI upset
Dose: Adult: 8-10 mg TDS
• Child: 4 mg BD for 1-5yr and 4 mg TDS for 5-10 year of age
20. GUAIFENESIN
• Guaifenesin or guaiphenesin also known as glyceryl guaiacolate
• It is derived from the tree from Guaiacum officinale
Indication :
• For productive cough
• It is used to reduce chest congestion caused by the common
cold, infections, or allergies
Side Effects:
• GI disturbance
• Dizziness
• Headache
• Drowsiness
Contraindication and precautions:
• hypersensitivity
• asthma, chronic bronchitis and emphysema
22. DRUG USED IN ASTHMA and COPD
Bronchodilators:
• Bronchodilators are a type of medication that make breathing
easier by relaxing the muscles in the lungs and widening the
airways (bronchi).
• They're often used to treat long-term conditions where the
airways may become narrow and inflamed, such as: asthma and
COPD
• Bronchodilators also help remove mucus from lungs. Open
airways mean mucus can move more freely, too, and you
can cough it up
23. CLASSIFICATION OF BRONCHODILATORS
Bronchodilators are classified into four categories:
1. Sympathomimetics:
a. Selective Beta2-Agonist: Salbutamol, terbutaline, salmeterol
b. Non-selective Beta2-Agonist: Isoprenaline
c. Non-selective and adrenergic agonist: Adrenaline,
isoprenaline, ephedrine, etc
2. Methylxanthines: Aminophylline, theophylline, theobromine,
etophylline
3. Muscarinic antagonists: Ipratropium bromide, oxitropium
bromide, tiotropium bromide etc
24. COMMONLY USED BRONCHODILATORS
Salbutamol
• Salbutamol is a direct-acting sympathomimetic with mainly
Beta-adrenergic activity and a selective action on Beta2 –
receptors.
• This results in its bronchodilation action being more prominent
than its effect on the heart.
Mechanism of action:
It is a Beta2 –receptor agonist and c-AMP production by
activating adenylate cyclase that results in leading to a smooth
muscle relaxation and bronchodilation via lower calcium
concentration.
25. Indication:
• asthma and COPD
• It also decreases uterine contractility and may be given as the
sulfate to arrest premature labour
Adverse effects:
• Hypertension
• Palpitation
• Angioedema
• Urticaria
• Headache
• Muscle cramps
• Dry mouth
• Tremor
• Anxiety
26. Contraindication and precautions:
• antepartum haemorrhage (in pregnancy or before labour)
• cardiac arrhythmia, hypertension, Ischaemic heart failure,
• thyrotoxicosis
• hypersensitivity,
DOSE:
• Adult: 2.5 to 5 mg inhalation; 2 to 4 mg PO
• Child: 0.25 mg/kg inhalation; 0.1 to 0.2 mg/kg PO
27. SALMETEROL
Salmeterol is a longer acting Beta2–adrenergic receptor agonist
used in the maintenance and prevention of asthma symptoms
and maintenance of COPD symptoms.
Mechanism of action:
• It binds to Beta2 –adrenergic receptor in which stimulation in
lungs results in the bronchial smooth muscle relaxation as well
as bronchodilation and increases bronchial air flow.
Indication :
• Used in the treatment of chronic bronchitis, COPD and exercise-
induced asthma
28. Contraindication and precautions:
Same as salbutamol.
Adverse effects:
Same as salbutamol
DOSE:
• Adult: 25 to 50 ug inhalation
• Child: 2 ug/kg inhalation
29. Methylxanthines
• These are a unique class of drug that are derived from the
purine base xanthine.
• Xanthine is produced naturally by both plants and animals.
• The aminophylline, theophylline are used in the treatment of
airways obstruction caused by conditions such as asthma,
chronic bronchitis
30. Mechanism of action:
• It inhibit phosphodiesterase enzyme (PDE) and increase levels
of cyclic adenosine monophosphate (cAMP) This signal results
in bronchial smooth muscle relaxation and cardiac stimulation
• It inhibit cell surface receptor for adenosine( that cause
contraction of airway smooth muscle)
Side effect:
- Arrhythmias - headache
- Insomnia - anxiety
- Neurotoxicity - GI disorder
- Nausea & vomiting - diarrhea
31. • Contraindication:
- Hypersensitivity - alcohol dependence
- Hypertension - GI disorder
Dose:
Theophylline:
5 mg/kg oral; 4-5 mg/kg as loading dose by IV infusion
Aminophylline:
100-350 mg oral; 350 mg daily IV
