ASPPB Psychopharmacology 4

Question 1

Which receptor mechanism explains why quetiapine at low doses (25–50 mg) is often used as a sleep aid?

Accepted Answer

H1 histamine receptor antagonism causing sedation

Answer

Quetiapine's strong H1 histamine blockade at low doses produces sedation before appreciable D2 or 5-HT2A blockade occurs.

Question 2

A child with ADHD and a tic disorder is being considered for stimulant therapy. The current evidence-based recommendation is:

Accepted Answer

Stimulants can be used; they do not consistently worsen tics and non-stimulants are an alternative

Answer

Current evidence shows stimulants do not reliably worsen tics in most children; alpha-2 agonists like guanfacine address both conditions.

Question 3

The mechanism by which disulfiram produces aversive effects when alcohol is consumed is:

Accepted Answer

Inhibiting aldehyde dehydrogenase, causing acetaldehyde accumulation

Answer

Disulfiram inhibits ALDH2, preventing acetaldehyde oxidation; acetaldehyde accumulation causes flushing, nausea, and tachycardia.

Question 4

Which antipsychotic has the greatest risk of QTc prolongation and is associated with torsades de pointes?

Accepted Answer

Thioridazine

Answer

Thioridazine carries a black-box warning for QTc prolongation and torsades de pointes, leading to restricted use.

Question 5

Gabapentin's mechanism of action in treating neuropathic pain and anxiety involves:

Accepted Answer

Binding to the alpha-2-delta subunit of voltage-gated calcium channels

Answer

Gabapentin binds the alpha-2-delta subunit of voltage-gated Ca²⁺ channels, reducing presynaptic calcium influx and neurotransmitter release.

(ASPPB) Association of State and Provincial Psychology Boards Practice Test