b-agonists in asthma act by all except -

Ans. is 'c' i.e., Decrease inflammation b-agonistso b2-receptors cause bronchodilatation, hence selective b2 agonists are used in bronchial asthma.o b2 agonists have no antiinflammatory action.o b2 agonists may be short acting (salbutamol, levalbuterol pirbuterol, terbutaline, Isoetharine, bitolterol, fenoterol, procaterol); or long acting (salmeterol, formoterol, arformoterol, carmoterol, indacterol).o Bambuterol is a long acting agent which is a prodrug of terbutaline. Bitolterol is also a prodrug and is activated to form calterol, by esterase in lung.o Inhaled b2-agonists are the most effective bronchodilators in asthma and hence are the agents of choice for treatment of acute attack of asthma.o Short acting b2-agonists produce bronchodilatation within 5 min and action lasts for 2-6 hrs - are used to abort and terminate acute asthma, but are not suitable for prophylaxis.o Salmeterol is delayed acting, can be used for prophylaxis only, while formoterol is fast acting and long acting can be used for both prophylaxis and acute attack.