My 87 Yr. Old Mother Has Dementia. The Doctor Prescribed

My 87 yr. old mother has dementia. The doctor prescribed torazadone (100 mg) to help her sleep and it is very effective. She often had "sundowner's syndrome" and would wander around the house while I slept... so this is a Godsend. There are also times when she is having auditory hallucinations and extreme agitation and confusion. Her doctor also prescribed hydroxyzine (25 mg 1/2-1 tablet as needed ) for those times when the agitation is at it's worst. My question is : IS it safe to give her the hydroxyzine when she has already taken her torazadone ? I don't want to over medicate her .