I Googled "Prozosin" and was redirected to "Prazosin". Since you are posting on the Sleep Disorder site, I assume that's why you've been prescribed this med. According to the following link, it's also recommended for a number of conditions, including high blood pressure, PTSD, enlarged prostate, CHF, Raynaud's disease, pheochromocytoma, and Ergot alkaloid poisoning.
http://www.everydayhealth.com/drugs/prazosin