Warning: I'm not a doctor!
However, I believe that unless noted on the bottled (or in the pamphlet that comes with most meds) that the medication must be taken with food I think you're fine taking them during a fast. To be sure, I'd call your doctor and ask him /her if it can be taken on empty.
I've taken antibiotics while fasting before and had no adverse effects. Then again, the anti's I was taking were supposed to be taken on empty.
If you don't mind me asking, what anti's are you taking, and for what condition? If you're not comfortable answering that, then don't.
There are dreams we’re taught are normal, whether it’s money or success or any of those things, but we shouldn’t believe in those things if they are not important to us. There is an ocean between our real lives and what is expected of us.” -Tim Lambesis