This is a strange day for you in the emergency department. Now you have to treat another normovolemic patient with acute drug-induced hypotension, and give the usually correct and effective dose of phenylephrine. This time the drug causes a vasopressor response that is far greater than you've ever encountered: systolic pressure rises dramatically, if not dangerously. Which of the following drugs did the patient most likely take an overdose of?
Correct Answer: D
Rationale: The correct answer is D: Reserpine. Reserpine is a drug that depletes catecholamines like norepinephrine and dopamine from nerve endings, leading to a prolonged and exaggerated response to sympathomimetic drugs like phenylephrine. This results in a dramatic increase in blood pressure when phenylephrine is given.
Rationale:
1. Atenolol (A) is a beta-blocker and would not lead to a vasopressor response.
2. Bethanechol (B) is a cholinergic agonist and would not lead to a vasopressor response.
3. Prazosin (C) is an alpha-1 adrenergic antagonist and would not lead to a vasopressor response.
In summary, Reserpine is the correct answer because it depletes catecholamines, leading to an exaggerated response to sympathomimetic drugs like phenylephrine, resulting in