Mechanism of action of coicosteroids in asthma is:-
Coicosteroids These are potent anti-inflammatory drugs and also decrease bronchial hyperreactivity and mucosal edema. Anti-inflammatory action is due to decreased recruitment of inflammatory cells as well as decreased production of PGs and LTs. These are not bronchodilators but increase the sensitivity to b2 agonists. Beta-2 agonists also increase the effect of steroids by enhancing the action of glucocoicoid receptors. Inhaled steroids include beclomethasone, budesonide, mometasone, fluticasone, flunisolide and triamcinolone. These have very little oral absorption and thus little systemic activity after inhalation (>90% reaches GIT after inhalational route, only 4-5% is retained in lungs). Hoarseness of voice and oropharyngeal candidiasis are very common adverse effects. Candidiasis can be prevented by gargling after each dose and topical nystatin (can be used for treatment also). Theophyllineincreases the effects of steroids byactivatingenzymehistone deacetylasewhich is the target for steroids as well.
Decreases mucosal edema by suppressing inflammatory response
Mast cell stabilization
Cause bronchodilation
Leukotriene receptor antagonism
Respiratory System