Which of the following is a long-acting beta 2 agonist

β2-agonists used in Asthma. Short-acting → Salbutamol, terbutaline Long-acting → Salmeterol, formoterol  Bambuterol is a prodrug of terbutaline. It is slowly hydrolysed by pseudocholinesterase.  Short-acting β2-agonists produce bronchodilation within 5 min and acting lasts for 2-6 hrs → are used to abort and terminate acute asthma, but are not suitable for prophylaxis.  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. Salbutamol & Terbutaline → Only for acute attack. Salmeterol → Only for prophylaxis. Formoterol → Both for prophylaxis and acute attack  Long-acting β2-agonists. (salmeterol & formoterol) are superior to short-acting β2-agonists (salbutamol & terbutaline), and equivalent to inhaled anticholinergics in COPD. Note: For one option go ahead with option ‘d’, i.e., adrenaline because amongst the given options, adrenaline is the shortest acting (60 - 90 minutes).  Salmeterol and formoterol are long-acting β2,-agonists.  Their lipophilic action is responsible for longer action → Lipophilic side chain anchors the drug in membrane adjacent to the receptor, slowing issue washout.