A 44-year-old male veteran presents to a psychiatric clinic with a 10-year history of PTSD related to combat trauma. He reports persistent intrusive memories, frequent nightmares occurring four to five nights per week, hypervigilance, emotional numbing, and avoidance of crowded places. His PCL-5 score is 58. He has been engaged in cognitive processing therapy for eight months with partial improvement in avoidance symptoms but persistent nightmares and hyperarousal. He has no comorbid substance use disorder and his only medication is lisinopril for hypertension. He has not previously tried psychotropic medications but is now requesting pharmacological support. The PMHNP is developing a medication management plan. Which approach is most appropriate?