73 Yr. Old Male Taking Meclizine (2/day For Dizziness/vertigo) As

73 yr. old male taking meclizine (2/day for dizziness/vertigo) as well as unisome (1 at night together with metroprolol tatrate), in the AM takes simvastatin, Plavix, centrum 50+; all 1 ea.) takes hyrochod/ace 5/325) 2/day)....he is all of the sudden the past few months having problems getting words spoken to him to his brain and desiffered (if you know what I mean). He understands you are talking to him and the words said but he said it is like it doesn't reach his brain. 3 yrs. ago went thru a stint surgery and coded on the table and paddles were used and he lost half his hearing and wears hearing aids now also). I think it may be a medication side effect or long term use, not sure but he said he didn't have it until a few months ago) Any ideas