Answer: Yes they can, but what can also happen is that the reason for why the antibiotics were needed in the first place eg and infection or being unwell is also impacting on the appetite. You don’t say how old she is or why she’s needed the AB’s, I would think that once she’s well and has finished the course then her appetite will return to normal. Sometimes AB’s can create some nausea and gut irritation and as you’d know yourself you can just feel a “bit off” when you’re taking them.
What’s important is that she’s still having plenty of milk via her breast milk or formula and she’s well hydrated. Six or more wet nappies a day is a good sign of adequate hydration. Don’t forget or hesitate to have her medically reviewed if you’re at all worried about her or she doesn’t seem to be improving.
Cheers
Jane