Hydroxyzine
"I had surgery and was prescribed hydroxyzine hcl 25 mg with my hydrocodone  for pain to keep from vomiting.  I took it every 6 hrs as prescribed, however I definitely had a severe reaction.  Night tremors and night paralysis and hallucinations.  I woke up thinking I was being followed by ghosts or that another episode where 2 teens were breaking into our house and I could do nothing.  My husband said I woke screaming of rats in the bed but have no memory of it.  Truly the scariest med I have ever been on."