I've been on it for around two years now. Pdoc started me on 1mg and slowly titrated up and it turned out 10mg is perfect for me. It really has worked well - i've gone from 4-5 hours frightening and broken sleep each night to 7 hours solid.

I've still had times when the nightmares/night terrors flared up again - mostly around particular trigger times - but it settles down much faster now. Only lose two or three nights, rather than several weeks!

(Although recently I was started on low-dose nortriptyline, for neuropathic pain, and that's giving me horrific nightmares - more generalised though, rather than trauma-specific. If it doesn't settle down soon i'm going to stop taking the nortrip so i can get my good sleep back.)

One thing to watch out for is changes to blood pressure. Prazosin lowers b/p, which for me worked out okay as my blood pressure was high, but if your friend's b/p is normal or low their doc would need to monitor it. Occasionally i get a bit dizzy if i stand up/get out of bed too fast, but that's the only side effect i've experienced (and i have a neck injury so that's more likely to be the cause anyway).