Pharmacology Autonomic Nervous System Agents 2

Question 1

A patient on prazosin for hypertension reports dizziness when standing up quickly. What is the mechanism behind this adverse effect?

Accepted Answer

Blockade of alpha-1 adrenergic receptors causing venous pooling

Answer

Stimulation of beta-2 receptors causing vasodilation

Answer

Inhibition of ACE reducing angiotensin II

Answer

Blockade of muscarinic receptors reducing heart rate

Question 2

Which cholinomimetic agent is used to reverse non-depolarizing neuromuscular blockade and acts by inhibiting acetylcholinesterase?

Accepted Answer

Neostigmine

Answer

Pilocarpine

Answer

Bethanechol

Answer

Carbachol

Question 3

A patient with pheochromocytoma is scheduled for surgery. Which drug class should be started FIRST to prevent hypertensive crisis during tumor manipulation?

Accepted Answer

Alpha-blockers before beta-blockers

Answer

Beta-blockers before alpha-blockers

Answer

Calcium channel blockers alone

Answer

ACE inhibitors alone

Question 4

Dobutamine is preferred over dopamine in cardiogenic shock primarily because it:

Accepted Answer

Selectively increases cardiac contractility with less peripheral vasoconstriction

Answer

Activates dopaminergic receptors to increase renal blood flow

Answer

Blocks alpha-1 receptors to reduce afterload

Answer

Stimulates beta-2 receptors to cause bronchodilation

Question 5

Which antimuscarinic drug is preferred for treating bradycardia during surgery due to its minimal CNS penetration?

Accepted Answer

Glycopyrrolate

Answer

Atropine

Answer

Scopolamine

Answer

Benztropine

Question 6

A patient taking a non-selective beta-blocker develops severe bronchospasm. Which adrenergic drug would be MOST appropriate to treat this?

Accepted Answer

Epinephrine

Answer

Metoprolol

Answer

Phenylephrine

Answer

Clonidine

Question 7

Physostigmine differs from neostigmine in clinical use primarily because physostigmine:

Accepted Answer

Crosses the blood-brain barrier and can reverse central anticholinergic syndrome

Answer

Is a quaternary amine with better peripheral selectivity

Answer

Has a longer duration of action

Answer

Is used exclusively to treat glaucoma