Sedative-hypnotics (tranquilizers, barbiturates, etc) may be helpful in the short term but are associated with tolerance and addiction potential.
In the central nervous system, alpha(1)-adrenergic receptors are known to be important in both the startle and sleep responses. Stimulation of these receptors may contribute to PTSD-related trauma-content nightmares. The alpha blocker Prazosin, (Vasoflex e.g.), an alpha(1)-adrenergic receptor blocker traditionally used to treat hypertension, has been shown to decrease trauma nightmares in both combat veterans and patients with non-combat-related PTSD.
The available data, although mostly from open-label trials, suggest that this agent also improves sleep quality and patients' sense of wellbeing and ability to function in daily activities. The optimum dose is still unknown; however, a dose-related response appears to be evident. Clinicians should monitor for orthostatic hypotension, usually seen early in therapy, when prazosin is started in patients with PTSD. Ongoing trials stand to reveal more specific findings and dosages.
Citation: Miller LJ. Prazosin for the treatment of posttraumatic stress disorder sleep disturbances. Pharmacotherapy. 2008 May; 28 (5): Pages 656-66.