Test 1 MOA MCQ | Quizlet

What is the primary mechanism of action of Tubocurarine?

A. Depolarizes NMJ by mimicking acetylcholine

B. Non-competitive NMDA antagonist

C. Competitive antagonist at nicotinic receptors (NMJ)

D. GABA-A receptor agonist

C

non-depolarizing neuromuscular blocker that competitively inhibits nicotinic receptors at the NMJ.

How does Atracurium induce muscle relaxation?

A. Enhances GABA-A receptor binding

B. Antagonizes muscarinic receptors

C. Inhibits calcium release from SR

D. Blocks acetylcholine at nicotinic receptors (NMJ)

D

Atracurium is a non-depolarizing neuromuscular blocker like tubocurarine.

What is the mechanism of Succinylcholine (Suxamethonium)?

A. Muscarinic receptor agonist

B. Acetylcholinesterase inhibitor

C. Depolarizing neuromuscular blocker

D. Opioid μ-receptor antagonist

C.

Succinylcholine mimics ACh, causing sustained depolarization and muscle paralysis.

How does Guaifenesin act in muscle relaxation?

A. Acts on nicotinic receptors

B. Enhances GABAergic inhibition

C. Centrally acts to depress interneurons

D. Blocks calcium channels

C

centrally acting muscle relaxant

What is the MOA of Dantrolene?

A. Muscarinic antagonist

B. Inhibits ryanodine receptors in skeletal muscle

C. Enhances chloride influx via GABA-A

D. Alpha-2 adrenergic agonist

B -

Dantrolene inhibits calcium release from the sarcoplasmic reticulum.

Bethanechol?

A. Cholinesterase inhibitor

B. Muscarinic receptor agonist

C. Muscarinic antagonist

D. Opioid receptor agonist

B

Bethanechol is a muscarinic agonist used to stimulate GI and urinary tract smooth muscle.

What is the primary mechanism of Neostigmine?

A. Irreversible acetylcholinesterase inhibition

B. Competitive nicotinic antagonist

C. Reversible acetylcholinesterase inhibitor

D. GABA-A agonist

C

ACH build up @ synapse

What is the MOA of Atropine sulfate?

A. Muscarinic antagonist

B. Alpha-1 blocker

C. Dopamine agonist

D. Serotonin reuptake inhibitor

A.

competitive muscarinic antagonist, reducing parasympathetic activity.

How does Scopolamine work pharmacologically?

A. Dopamine antagonist

B. Muscarinic antagonist (CNS-active)

C. Beta-adrenergic agonist

D. Alpha-2 agonist

B

What is the MOA of Glycopyrrolate?

A. Dopamine D2 antagonist

B. Peripheral muscarinic antagonist

C. Alpha-1 blocker

D. Opioid agonist

B

Limited CNS penetration

What is the mechanism of Acepromazine?

A. Serotonin antagonist

B. Dopamine receptor antagonist (D2)

C. Alpha-2 agonist

D. Beta-adrenergic blocker

B

Acepromazine blocks dopamine receptors, producing sedation and tranquilization.

What is the MOA of Diazepam?

A. Alpha-2 agonist

B. Enhances GABA-A activity (benzodiazepine)

C. Anticholinergic

D. NMDA antagonist

B - Diazepam enhances GABA-A receptor-mediated inhibition.

13. How does Midazolam act?

A. GABA-A agonist

B. Cholinesterase inhibitor

C. Opioid receptor agonist

D. Serotonin antagonist

A - Midazolam is a benzodiazepine that enhances GABA-A receptor function.

What is the mechanism of Hydroxyzine?

A. H2-receptor antagonist

B. H1-receptor antagonist

C. GABA-B agonist

D. Serotonin reuptake inhibitor

B - Hydroxyzine is a histamine H1 antagonist with sedative and anti-emetic properties.

What is the MOA of Pentobarbital?

A. NMDA receptor blockade

B. Enhances GABA-A receptor activity

C. Dopamine antagonist

D. Alpha-2 agonist

B - Pentobarbital is a barbiturate that enhances GABA-A-mediated inhibition.

How does Lidocaine work as a local anesthetic?

A. Blocks GABA-A channels

B. Blocks sodium channels

C. Antagonizes NMDA receptors

D. Inhibits serotonin reuptake

B - Lidocaine blocks voltage-gated Na⁺ channels, preventing nerve conduction.

What is the MOA of Propofol?

A. NMDA antagonist

B. Enhances GABA-A receptor activation

C. Muscarinic antagonist

D. Sodium channel blocker

B - Propofol enhances GABA-A activity, causing sedation and anesthesia.

How does Thiopental act?

A. Dopamine antagonist

B. Barbiturate: GABA-A modulator

C. Opioid agonist

D. Alpha-2 adrenergic agonist

B - Thiopental is a barbiturate that enhances GABAergic inhibition.

What is the mechanism of Ketamine?

A. Alpha-1 blocker

B. NMDA receptor antagonist

C. Muscarinic antagonist

D. GABA-B agonist

B - Ketamine is a non-competitive NMDA receptor antagonist

How does Morphine work?

A. GABA-A enhancer

B. Full μ-opioid receptor agonist

C. Beta-blocker

D. Serotonin antagonist

B - Morphine is a full μ-opioid receptor agonist providing analgesia and sedation.

What is the MOA of Butorphanol?

A. Full μ-agonist

B. NMDA blocker

C. Partial μ-antagonist, κ-agonist

D. GABA-B antagonist

C - Butorphanol is a κ-opioid receptor agonist and partial μ-antagonist.

What is the function of Naloxone?

A. Muscarinic antagonist

B. Serotonin agonist

C. Opioid receptor antagonist

D. GABA-A agonist

C - Naloxone is a pure opioid antagonist (μ, κ, δ).

What is the MOA of Imipramine?

A. Serotonin and norepinephrine reuptake inhibitor (TCA)

B. SSRI

C. Dopamine antagonist

D. MAOI

A - Imipramine is a TCA that blocks serotonin and NE reuptake.

How does Fluoxetine work?

A. Inhibits MAO

B. Blocks dopamine transporters

C. Selectively inhibits serotonin reuptake

D. Blocks sodium channels

C - Fluoxetine is a Selective Serotonin Reuptake Inhibitor (SSRI).

What is the MOA of Caffeine?

A. Beta-agonist

B. Adenosine receptor antagonist

C. GABA-B agonist

D. Dopamine D2 antagonist

B - Caffeine blocks adenosine receptors and stimulates CNS activity.

What is the MOA of Flunixin?

A. COX-2 selective inhibitor

B. Non-selective COX inhibitor

C. Alpha-1 antagonist

D. Serotonin antagonist

B - Flunixin is a non-selective COX inhibitor, reducing prostaglandin synthesis.