Moa and adverse effects

1. DRUGS USED IN ASTHMA
[Anti-asthmatic drugs]
 Asthma is an Chronic inflammatory disorder of the airways in which many cells and
cellular elements play a role.
 this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness,
and coughing, particularly at night or in the early morning.
 Morbidity and mortality highly correlated with poverty, urban air quality, indoor allergens,
lack of patient education, and inadequate medical care
 About 5000 deaths annually.

3.  Allergens
 Dust mites, mold spores, pollen, indoor and outdoor pollutants, irritants (smoke,
perfumes, cleaning agents).
 Pharmacologic agents; ASA[acetyl salicylic acid], beta-blockers.
 Physical triggers (exercise, cold air, distilled water, and sulfur dioxide).
 Diseases; viral and bacterial URI[upper respiratory infection ], rhinitis

4. CLASSIFICATION
1.BRONCHODILATORS
 A.Sympathomimetics
Short Acting: Salbutamol, Terbutaline
Long Acting: Formeterol, Salmetrol, Bambuterol
 Mechanism of Action -
Beta-2 adrenergic agonist, when administered binds beta 2 receptors
Stimulation of adenylate cyclase
Increase cAMP
Bronchodilation and decreased muscular tone.

5.  B.Methylxanthine: Aminophylline, Theophylline
 Mechanism of Action
1. Inhibit Phosphodiestrase Enzyme (which catalyzes breakdown of cAMP).
Increase cAMP
Dephosphorylation of MLC
Bronchodilation
2. Increased intracellular calcium
3.Decrease contractility of bronchiolar smooth muscles.
 C. Anticholinergics: Ipratropium, Oxytropiu, Tiotropium
 Mechanism of Action
Blockade of muscarinic receptors present in bronchi and bronchioles
Decrease mucus viscosity
Increase mucociliary clearance

6. 2.Leukotriene Receptor Antagonists
Montelukast – oral
Zafirlukast – (Cingular) oral administration for control of asthma
 Leukotrines are products of arachidonic acid metabolism. They are released at the site of
inflammation producing bronchoconstriction having contributory effect to inflammation and
bronchoconstriction.
 Mechanism of Action
Montelukast and Zafirlukast are competitive antagonists.
Inhibits cysteinlyl leukotriene Cys LT1 receptor relieving bronchospasm and bronchoconstriction.
Inhibit physiologic actions
One drug blocks synthesis of 5 lipooxygenase and is hepatotoxic Zileuton. Half like is 2.5 hours

7.  3.Mast Cell Stabilizers
Na chromoglycate inhalation
Nedocromil
Ketotifen- (5HT action) oral
 Mechanism of Action
Stabilize mast cells membrane and inhibit release of chemical mediators
Depress exaggerated neuronal reflexes triggered by stimulation of irritant receptors.
Depress axonal reflexes which release inflammatory neuropeptides.
Inhibit release of cytokines from T-CELLS.

8.  4.Corticosteroids
Hydrocortisone I/V
Prednisolone oral
Betamethosone Beclomethasone inhalation
Budesonide
Flucitasone
 Mechanism of Action
Anti inflammatory action Decrease mucosal oedema, mucus secretion and reduce capillary permeability Stabilize
mast cells Block immune response, decrease antibody formation Antagonise histaminergic and cholinergic
responses Enhance beta-2 adrenoceptor responsiveness to agonists (Catecholamines)

9.  5.Monoclonal Antibodies:
 Omalizumab
They bind to IgE antibodies present on mast cells. If administered I/V or
subcutaneously, humanized monoclonal antibodies decrease levels of IgE antibodies,
decreasing tendency of severe asthma, in both phases (immediate/delayed)

10. ADVERSE EFFECTS
 Some side effects of medications have been noted to include tremor,
increased nervousness and insomnia in children, nausea, fever,
bronchospasm, vomiting, headache, pain, dizziness, cough, allergic
reaction, dry mouth, sweating, chills, and dyspepsia.