PTSD Pharmacology & Medication Management 3 — Questions and Answers
Question 1: Paroxetine is FDA-approved for PTSD. Compared to sertraline, what is a notable pharmacokinetic concern with paroxetine?
- Longer half-life requiring weekly dosing
- Significant CYP2D6 inhibition and shorter half-life increasing discontinuation risk (Correct answer)
- Renal clearance requiring dose adjustment in all patients
- Narrow therapeutic index requiring plasma level monitoring
Correct answer: Significant CYP2D6 inhibition and shorter half-life increasing discontinuation risk
Paroxetine inhibits CYP2D6 and has a shorter half-life, making it more prone to causing discontinuation syndrome and drug-drug interactions than sertraline.
Question 2: Which neurotransmitter system does prazosin target to reduce PTSD nightmares, and what is its mechanism?
- Serotonin system via 5-HT2A antagonism
- Dopamine system via D2 blockade
- Norepinephrine system via alpha-1 receptor antagonism (Correct answer)
- GABA system via positive allosteric modulation
Correct answer: Norepinephrine system via alpha-1 receptor antagonism
Prazosin blocks alpha-1 adrenergic receptors, reducing the central noradrenergic hyperactivation that drives PTSD nightmares and sleep disturbances.
Question 3: A clinician considers topiramate for a patient with PTSD. What is topiramate's proposed mechanism relevant to PTSD?
- Serotonin reuptake inhibition
- NMDA receptor agonism
- Glutamate modulation and GABA potentiation (Correct answer)
- Dopamine D4 receptor blockade
Correct answer: Glutamate modulation and GABA potentiation
Topiramate modulates glutamate activity and potentiates GABA, which may reduce traumatic memory reconsolidation and hyperarousal in PTSD.
Question 4: D-cycloserine has been investigated as an adjunct to PTSD psychotherapy. What is its proposed role?
- Sedation to reduce anxiety during sessions
- NMDA partial agonism to enhance fear extinction learning (Correct answer)
- Blocking norepinephrine to prevent encoding of new fears
- Serotonin augmentation to improve mood
Correct answer: NMDA partial agonism to enhance fear extinction learning
D-cycloserine is an NMDA partial agonist hypothesized to enhance fear extinction by facilitating synaptic plasticity during exposure-based therapy sessions.
Question 5: A patient with PTSD also has alcohol use disorder. Which PTSD medication is most appropriate to use cautiously due to additive CNS depression risk?
- Sertraline
- Prazosin
- Quetiapine (Correct answer)
- Paroxetine
Correct answer: Quetiapine
Quetiapine carries significant CNS sedation and should be used cautiously in patients with alcohol use disorder due to additive CNS depression and aspiration risk.
Question 6: What is the primary reason hydrocortisone (cortisol) is being researched as a prophylactic agent shortly after trauma exposure?
- It blocks dopamine release preventing reward sensitization
- It may prevent pathological fear memory consolidation by modulating glucocorticoid receptors (Correct answer)
- It enhances serotonin synthesis in the amygdala
- It prevents acute stress disorder by inducing sleep
Correct answer: It may prevent pathological fear memory consolidation by modulating glucocorticoid receptors
Early cortisol administration may interfere with pathological fear memory consolidation by acting on glucocorticoid receptors in the amygdala and hippocampus.
Question 7: When discontinuing an SSRI in a patient with PTSD after successful treatment, what is the recommended minimum treatment duration before tapering?
- 4 weeks
- 3 months
- 12 months (Correct answer)
- 5 years
Correct answer: 12 months
Most guidelines recommend maintaining SSRI treatment for at least 12 months after symptom remission in PTSD before considering a gradual taper.
PTSD Pharmacology & Medication Management 3
Paroxetine is FDA-approved for PTSD.
Compared to sertraline, what is a notable pharmacokinetic concern with paroxetine?