ASPPB Psychopharmacology 2 — Questions and Answers
Question 1: A patient on lithium reports coarse tremor, confusion, and vomiting. Serum lithium is 2.4 mEq/L. The most appropriate intervention is:
- Reduce lithium dose by 50%
- Discontinue lithium and initiate hemodialysis (Correct answer)
- Add propranolol for tremor management
- Switch to valproate immediately
Correct answer: Discontinue lithium and initiate hemodialysis
Lithium levels above 2.0 mEq/L with neurological symptoms indicate severe toxicity requiring discontinuation and often hemodialysis.
Question 2: Which antidepressant mechanism is most associated with priapism as a side effect?
- SSRIs via serotonin 2A antagonism
- Trazodone via alpha-1 adrenergic blockade (Correct answer)
- MAOIs via irreversible enzyme inhibition
- TCAs via muscarinic blockade
Correct answer: Trazodone via alpha-1 adrenergic blockade
Trazodone's alpha-1 adrenergic blockade impairs penile detumescence, making priapism a notable risk.
Question 3: A prescribing psychologist considers augmenting an SSRI non-responder with aripiprazole. Aripiprazole's primary mechanism that aids antidepressant augmentation is:
- Full dopamine D2 agonism
- Partial D2 and 5-HT1A agonism with 5-HT2A antagonism (Correct answer)
- Norepinephrine reuptake inhibition
- GABA-A positive allosteric modulation
Correct answer: Partial D2 and 5-HT1A agonism with 5-HT2A antagonism
Aripiprazole is a partial D2/D3 and 5-HT1A agonist plus 5-HT2A antagonist, which modulates dopaminergic and serotonergic tone to enhance antidepressant response.
Question 4: Which pharmacokinetic parameter best describes the relationship between a drug's dose and its plasma concentration at steady state?
- Volume of distribution
- Half-life
- Clearance (Correct answer)
- Bioavailability
Correct answer: Clearance
Clearance determines steady-state plasma concentration for a given dose rate; higher clearance means lower steady-state levels.
Question 5: Naltrexone is used in alcohol use disorder primarily because it:
- Produces aversive reactions when alcohol is consumed
- Blocks opioid receptors, reducing alcohol's rewarding effects (Correct answer)
- Reduces GABA withdrawal-related seizure risk
- Inhibits aldehyde dehydrogenase
Correct answer: Blocks opioid receptors, reducing alcohol's rewarding effects
Naltrexone blocks mu-opioid receptors, attenuating the dopaminergic reward signal triggered by alcohol consumption.
Question 6: A patient taking phenelzine eats aged cheese and develops severe hypertension. This reaction is caused by:
- Serotonin accumulation in platelets
- Inhibition of intestinal MAO-A preventing tyramine breakdown (Correct answer)
- Direct tyramine-receptor agonism at alpha-2 receptors
- Inhibition of COMT increasing catecholamine synthesis
Correct answer: Inhibition of intestinal MAO-A preventing tyramine breakdown
MAO-A in the gut normally metabolizes dietary tyramine; MAOI blockade allows tyramine to enter systemic circulation and trigger catecholamine release.
Question 7: Clozapine requires mandatory hematological monitoring because of a risk of:
- Thrombocytopenia leading to bleeding
- Agranulocytosis that can be fatal (Correct answer)
- Megaloblastic anemia from folate depletion
- Hemolytic anemia via immune complex formation
Correct answer: Agranulocytosis that can be fatal
Clozapine carries a 1–2% risk of potentially fatal agranulocytosis, requiring regular ANC monitoring through the REMS program.
ASPPB Psychopharmacology 2
A patient on lithium reports coarse tremor, confusion, and vomiting.
Serum lithium is 2.4 mEq/L.
The most appropriate intervention is: