This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
Reflex tachycardia is most likely to occur after the systemic administration of 
Select and explain. 
A. albuterol, B. methoxamine, C. phenylephrine, D. propranolol
A: albuterol
Answer: A: albuterol 
Explanation: Although used primarily via inhalation for asthma, systemic effects of albuterol include vasodilation due to its b2 receptor activation. This can result in a decrease in PVR and mean BP, which elicits a reflex tachycardia. Methoxamine and phenylephrine are a- receptor activators causing vasoconstriction, which would result in reflex bradycardia. Ganglion blockers (trimethaphan) prevent autonomic reflexes, and a reflex increase in heart rate could not occur in the presence of a beta blocker (propranolol).