This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Pharmacology), Subject name: Pharmacology
A 70 years old man was administered penicillin i.v. Within 5 minutes, he developed generalized urticaria, swelling of lips, hypotension and bronchospasm. The first choice is to administer: 
Select and explain. 
A. Chlorpheniramine inj, B. Epinephrine inj., C. High dose hydrocortisone tablet, D. Nebulized salbutamol
B: Epinephrine inj.
Answer: B: Epinephrine inj. 
Explanation: Ans. (B) Epinephrine inj (Ref: KDT 8th/e p149)Epinephrine (adrenaline) is the drug of choice for anaphylactic shock. It is given by s.c. or i.m. route in a concentration of 1:1000. Intravenous route is rarely used but at much lower (1:10,000) concentration.