I think those are handled a bit differently at every school. As long as the rest of your academic record looks fine and you have a logical reason for doing them that way then I doubt too many people would balk at it. But if there are any questions about your academic abilities then the first thing that's gonna come up is that you took those courses online so it must mean you were trying to find an easier way out. If you're really concerned, talk to your closest med schools admissions department about it and see what they have to say.