The correct answer is D. Prazosin is an alpha 1-adrenergic receptor blocker that has been shown to reduce nighttime PTSD symptoms including trauma-related nightmares and distressed awakenings. It has also been shown to increase total sleep time in patients with PTSD. Prazosin is thought to improve sleep by blocking adrenergic activity in the central sympathetic nervous system, decreasing the stress response and sympathetic arousal that is associated with PTSD symptoms, including nightmares. SSRIs are first line in the pharmacotherapy of PTSD, and prazosin should be considered as an adjunct therapy for patients with nighttime symptoms. A) Clonezepam is incorrect. While benzodiazepines may be used for treating anxiety and hyperarousal in PTSD, their use is not well supported in the research literature. In addition, this patient has a history of alcohol use disorder and medications with addictive properties would best be avoided if possible. B) Chlorpromazine is incorrect. While it does have sedating effects, it is a first generation antipsychotic and is not used in the treatment of PTSD. C) Quetiapine is incorrect. There is limited evidence for the efficacy of second generation antipsychotics as both monotherapy and augmentation in patients with PTSD. Prazosin has more convincing evidence for augmentation with SSRI therapy, specifically for nighttime symptoms.

Publication reference : aylor FB et al. Prazosin effects on objective sleep measures and clinical symptoms in civilian trauma posttraumatic stress disorder: a placebo-controlled study. Biol Psychiatry. 2008 Mar 15;63(6):629-32. PubMed PMID: 17868655; PubMed Central PMCID: PMC2350188.
Reference URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2350188/