What we've used in the clinic is prazosin. It's an alpha-1 antagonist that has been very useful. Actually, it's the medication that had the most evidence for treating nightmares related to post-traumatic stress, sleep disturbances, and insomnia as well.
There are two issues we have with pharmacological agents. One is what can we use in theatre that is safe, because people need to wake up quickly oftentimes and be ready to perform, and you don't want to have any of the residual hypnotic or sedative effects.
With people with post-traumatic stress, our typical sleep medications perform very poorly, except for prazosin. There are plenty of different agents that have been used with mitigated success. I think for pharmacological intervention, generally speaking, it's really an art combined with science to personalize what is the exact agent or combination of agents that will help people most in terms of sleep, and have the least residual side effects.