My 77 Year Old Male Father In Law Is On

My 77 year old male father in law is on his 6th day of IV ertapenem for an ecoli infection He has suffered a few strokes years ago He is also in early stages of dementia I am concerned because his leg strength and balance has decreased since these treatments have begun. He has 2 more days to go The symptoms he was prescribed the medication for seem to be improving but the body weakness concerns me