High-dose prazosin for the treatment of post-traumatic stress disorder.

Patients with post-traumatic stress disorder (PTSD) are frequently symptomatic despite being on medications currently approved by the US Food and Drug Administration for PTSD. There is evidence to support the notion that prazosin is effective for PTSD nightmares. However, PTSD-related nightmares often do not resolve completely on a low dose of prazosin. The capacity of prazosin to treat daytime symptoms of PTSD which are distressing to patients has not been well studied. Clinicians are reluctant to increase the dose of prazosin due to side effect concerns. To date, the highest reported dose of prazosin used for PTSD is 16 mg daily. We illustrate two case reports using high-dose (up to 30 and 45 mg) prazosin for PTSD with comorbid treatment-resistant mood disorders. We report that high-dose prazosin was safe, tolerable and effective for PTSD in adults. To our knowledge, this is the first case series to highlight the importance of using high-dose prazosin for the treatment of PTSD. In patients with partial response to currently available medications for PTSD, greater utilization of high-dose prazosin for the management of PTSD may lead to better outcomes.