"i had a scary adverse reaction with ativan. i was given 1 mg in the hospital orally for the very bad anxiety i was having. about an hour and a half later i began getting the most strangest, scariest hallucinations. both visual and sensory. i don&#039;t know if this was an allergic reaction but i never had this problem with any other benzodiazepine. please be cautious with ativan in particular, because it altered the functioning of my brain (it wore off the next day)."