My Daughter, 22 Had Nausea Two Weeks Ago, But It

My daughter, 22 had nausea two weeks ago, but it went away. Now, the nausea and vomiting is persistent and has been going on for about 5 hours. Tried giving her rice water, clear liquids and everything comes back up. I've heard that Benedryl has the same ingredient as finagrin(sp), but am hesitant and do not know what to tell her husband to do for her. Any suggestions?