The generic name is hydroxyzine. It's sold as Vistiril, Atarax, and a dozen other names. It's a sedative type histamine used for anxiety relief and sometimes sedation. It can help, but only use as prescribed. PS..It's pretty drying to the mouth and mucus membranes. Have some hard candy on hand.
I didn't find anything under Vistrel, but here's what I found researching it under different spellings: (Hope this comes out, I am copying and pasting)
OK, so it won't work - sorry. I found it under Vistaril, and it's used for itching, and anxiety and has sedative properties, so maybe it would help you sleep? It says a lot of different stuff, but I can't concentrate that well right now.
I haven't had much sleep in days, so I know how you feel, hang in there.