100% Correct Questions & A Grade Verified Answers
A 29-year-old woman presents with her first major depressive episode. She has no
comorbidities and requires an initial antidepressant. Which receptor profile of sertraline
primarily underlies its first-line recommendation?
A) Potent blockade of D2 receptors to augment dopamine
B) Selective inhibition of the presynaptic serotonin re-uptake transporter (SERT)
C) Full agonism at the mu-opioid receptor for mood elevation
1. D) Non-selective inhibition of both MAO-A and MAO-B enzymes
Answer: B
Rationale: SSRIs such as sertraline selectively block SERT, increasing synaptic 5-HT and
promoting downstream neuroplasticity without the complex receptor interactions or
dietary restrictions seen in options A/C/D.
A third-year medical student asks why fluoxetine can cause nausea early in therapy.
Which serotonergic receptor in the gut is most responsible?
A) 5-HT3 receptor
B) 5-HT2A receptor
C) 5-HT1A receptor
2. D) 5-HT7 receptor
Answer: A
Rationale: Gut 5-HT3 receptor activation by increased serotonin triggers vagal afferent
nausea pathways; this is why SSRIs often cause transient nausea and why 5-HT3
antagonists (e.g., ondansetron) can alleviate it.
A 34-year-old man develops erectile dysfunction 6 weeks after starting paroxetine.
Which receptor-mediated mechanism best explains SSRI-induced sexual dysfunction?
A) Alpha-1 adrenergic blockade reducing vasodilation
B) Increased serotonergic tone inhibiting dopaminergic pathways in the mesolimbic
system
,C) Direct antagonism of testosterone synthesis in the testes
3. D) Muscarinic M3 receptor agonism impairing smooth muscle relaxation
Answer: B
Rationale: Elevated 5-HT levels inhibit dopaminergic reward circuits including
nigrostriatal and mesolimbic pathways, decreasing libido and arousal; this is a central,
not peripheral hormonal, effect.
A patient on escitalopram for 8 days develops irritability, insomnia, and akathisia. Which
term best describes this early activation syndrome?
A) Serotonin syndrome
B) Antidepressant-induced jitteriness/anxiety
C) Neuroleptic malignant syndrome
4. D) Treatment-emergent mania
Answer: B
Rationale: “Jitteriness” is a common early transient phenomenon due to rapid 5-HT
increase before downstream adaptive changes; it is not the full serotonin syndrome (A)
nor represents mania (D) at this stage.
A patient with melancholic depression is switched from sertraline to phenelzine. Which
dietary instruction is essential to prevent tyramine-induced hypertensive crisis?
A) Limit foods aged, fermented, or pickled (e.g., aged cheese, sauerkraut)
B) Avoid all dairy products regardless of age
C) Increase caffeine to counteract MAOI fatigue
5. D) Drink grapefruit juice to enhance MAOI levels
Answer: A
Rationale: MAO-A inhibition in the gut prevents tyramine breakdown; tyramine-rich foods
release norepinephrine and can cause severe hypertension. Fresh dairy (B) is safe;
caffeine (C) and grapefruit (D) do not address tyramine risk.
, A 26-year-old female is started on venlafaxine XR. At 4 weeks she reports sustained
elevation in BP (148/94 mmHg). Which receptor action of venlafaxine at higher doses
most likely contributes to this effect?
A) 5-HT3 antagonism
B) Norepinephrine re-uptake inhibition
C) D2 receptor blockade
6. D) H1 receptor agonism
Answer: B
Rationale: Venlafaxine’s NE re-uptake blockade at doses ≥150 mg/day increases
sympathetic tone and can elevate BP, requiring monitoring and possible dose reduction
or switch.
A patient inquires why duloxetine might help both depression and chronic pain. Which
shared neurotransmitter pathway underlies this dual benefit?
A) Descending serotonergic-noradrenergic pain inhibitory pathways in the spinal cord
B) Dopaminergic reward circuits in the nucleus accumbens
C) GABAergic interneurons in the amygdala
7. D) Histaminergic tuberomammillary projections
Answer: A
Rationale: Enhanced 5-HT and NE in the descending dorsal horn tracts inhibit
nociceptive signaling, providing analgesia independent of mood improvement.
A patient develops urinary retention on imipramine 150 mg daily. Which receptor binding
best explains this anticholinergic adverse effect?
A) Muscarinic M3 receptor antagonism in the detrusor
B) Alpha-1 adrenergic receptor blockade in the bladder neck
C) 5-HT2C receptor agonism in the pontine micturition center
8. D) Nicotinic NMDA receptor antagonism in the pelvic floor
Answer: A