This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: COPD and Asthma, Subject name: Medicine
Which drug are not used in severe persistent Asthma? 
Select and explain. 
A. Sho-acting beta 2 agonist, B. Oral coicosteroids, C. Long-acting beta 2 agonist, D. Inhaled high dose Steroids
B: Oral coicosteroids
Answer: B: Oral coicosteroids 
Explanation: Oral coicosteroids are given in very severe persistent asthma and not severe persistent asthma. Sho acting beta 2 agonists are used for emergency management of acute asthma. Regular prolonged usage of S.A.B.A /salbutamol results in tachyphylaxis and tolerance to the effects of the drug. Hence S.A.B.A should be used for symptomatic relief as and when required. L.A.B.A with inhaled high dose steroids is used for the management of severe persistent asthma.