I also pretty much agree with Jennifer's advise. My son was getting extrmemly high fevers anually pretty much from ages 4-8 and I was taking him to the Dr & Urgent Care All THE Time. I remember one week I took him to the Dr.'s office Monday, Wednesday, & Friday, and then to the ER on Saturday, to be told by everyone that he had a virus there was nothing they could do except make him comfortable. It was explained to me that the fever is the body's way of naturally getting rid of the infection, and each body has a different temperature that works for that body. I do know it's hard to watch your little guy with that fever, but in my experience with my son, just waiting it out worked the best.
In your situation, I do wonder if he was diagnosed properly. If he has a viral infection, antibiotics won't work with it, just time, rest, and fluids.
Good Luck, I know it's hard!