I had withdrawn database course due to some medical reason and retook it the following semester. Got accepted into Columbia and CMU, rejected by Princeton.
Personally, I feel as long as you have a good reason for it, it shouldn't be much a problem. During the CMU interview, they did ask me why I withdrew , whether I retook it , and what grade I got when I retook the course (luckily, i got A+) . I just explained my medical leave and it was all fine.