Asthma derived from Greek word
- To stay awake in order to breath
Difficulty in breathing
Asthma is a chronic inflammatory
disease in which patient suffers with
reversible episodes of airway
obstruction due to bronchial hyper
-Due to bronchial
It has 2phases
Recurrent episodic coughing
Shortness of breathing
Symptoms are worsening at night
Asthma described as two type
(Atopic extrinsic asthma)
It is associated with
exposure of specific
Ex:- House dust, pollen
It is episodic and less
prone to develop to
(Non atopic extrinsic asthma)
It is associated with
some non specific
Ex:- chemical irritants
It is perenial and prone
to develop to status
Allergen enter (Foreign body)
Immunological reaction (AG:AB Complex formation)
Circulation in blood
Basophiles, Neutrophilis engulf
Whenever same allergen re exposed
Activation of AG:AB complex
Reacts with lung mast cells
(Degranulation of mast cells)
(Like Histamine,5HT,PGs,LT4, Cytokines)
Histamine, LTC4, LTD4, LTB4,
Cytokines, Adenosine, PGD2, PAF,
ECP and Neuropeptides
Cause inflammation, oedema,
bronchospasm, muscus secretion,
In early phase these
mediators leads to
In late phase
It divided into two categories
1. Short term relievers.( Bronchodilators)
2. Long term controllers.
Bronchial Smooth Muscle
ß2 receptors are present in the airway
smooth muscle. cause Bronchodilatation
These are only provide relief
Release of broncho constricting mediators
from mast cells
Inhibit macrovascular leakage
Rapid bronchodilator when SC/inhaled(320µg/puff)
Onset of action 15min after inhalation
Duration of action:60-90min.
ADR:- Acts on β1 receptor cause
So rarely prescribed.
Ephedrine: α,β1, β2
Ephedrine has a longer action
Pronounced central effects.
Short acting : Terbutaline, Salnutamol
On inhalation they have rapid onset(1-5Min)
Short duration of action preferred for acute attack
Route: Inhalation 100-200µg/6hourly
Other MDI, Oral, IM, IV
Terbutaline is the only one drug safely used during
Long acting: Salmeterol, bambutarol
Long acting but slow onset of action
Preferred for maintenance therapy
Not useful in acute attack due to slow onset of
Route: Inhalation 50µg twice daily.
Preferred for prophylaxis due to long acting
Route: Inhalation 12-24µg twice daily
ADR of Sympathomimetics
By oral route stimulate β2 receptors in skeletal
muscle cause tremors, Orthostatic hypotension.
Tachycardia (High dos also stimulate β1
receptors in heart)
Less effective then β agonists
MOA: By blocking M3 receptors on air way smooth
muscle and prevents Ach action.
-They acts by cGMP levels in bronchial smooth
-Poor absorption from bronchi into systemic
-Do not cross BBB.
-Also mucus secretion
Ipatropium + β2 (Salbutamol) work better in serve
asthma and long duration of action
i) Inhibition of PDE 3,4. These enzyme are responsible
for metabolism of cAMP.
ii) Blockade of Adenosine receptors.
Theophyline exhibits bronchodilatory action
Food delay the rate of absorption
Cross placental & BBB
Metabolized in Liver
Excreted in urine
Glucocorticosteriods induce synthesis of lipocotrin
which inhibits pholipaseA2 there by preventing
formation of mediators such as PGs,TAX2, LTand
Actions: Anti allergic, anti inflammatory,
immunosuppressant ( AG:AB reactions ), Mucosal
oedema, bronchial hyperactivity, Enhance β
adrenergic action by up regulation of β2 receptors in
Inhalator glucocorticosteriods such as
beclomethasone, budesonide and fluticasone are
used as prophylactic agents in asthma.
less systemic side effects.
Common side effects:
Dryness of mouth
Systemic are used in acute severe and chronic severe
Mast cell stabilizers
Non bronchodilating, Non steroid drugs, used for prophylactic
Prevent degranulation and release of chemical mediators from
the mast cells.
They stabilize the mast cells by preventing transmembarane
influx of Ca ions.
Least systemic absorption
Uses: Allergic asthma, allergic conjunctivitis, allergic rhinitis,
Ketotifen (Mast stab.+ Antihistamincs)
LT are powerful bronchoconstrictors.
Action by preventing their synthesis or blocking
effect on cys LT receptors
Synthesis inhibitors (Lipooxygenase)
Well absorbed after oral administration
Highly bound to plasma protein
Metabolized by liver
Effective for prophylactic treat of mild asthma.
Zileuton cause hepatic toxicity.
Monoclonal anti IgE antibody
MOA:- AG:Ab complex formation by AB action
Omalizumab: Recombinant humanized
Inhibit the binding site of IgE to mast cells and
PK: administered parentarally
Uses: Moderate to severe asthma and allergic
Indicated for asthmatic patients who are not
adequately controlled by inhalational
ADR: Inj site redness, itching, stinging.
NO: It dilate pulmonary blood vessels and
relax airway smooth muscle.
Uses: For acute severe asthma and
management of pulmonary hypertension.
Ca channel blockers:
Broncho constriction ultimately involves
some degree of ca into cells Nefedpine /
Verapamil should provide relief in asthma.
RX Status asthmatics (Acute severe asthma)
Status asthmatics a severe acute
asthma, which is a life threatening
condition involving exhaustion,
dehydration and metabolic
Humidified O2 inhalation
Neubulized β2 adrenergic agonist + anti
Systemic glucocorticosteroids IV
IV fluids to correct dehydration.
K supplements: To correct hypokalemia
produced by repeated administration of
NaHCo3 (Sodium bicarbonate) to treat
Antibiotics to treat infection
DRUGS TO BE AVOIDED IN ASTHMA
β adrenergic blockers
NSAIDS ( cause hyperapoenia) except