Why would it be more difficult to treat diseases in humans caused by members of the Eucarya than diseases caused by the Bacteria?

The organisms that cause the diseases that we are looking at and human cells are both eukaryotic cells, so only certain drug can be used to rid the both of the infection without harming the human body. When we use antibiotics to kill bacteria, it is usually targeted at the cell wall. This doesn't kill human cells because their cells don't have a cell wall.