AP credits are more for college. They will help you place out of some science classes. Medical schools do not 'accept' AP credits per se; some are more interested in seeing how you do in a college-evvironment class than if you learned the material in high school.
Example: Most medical school require a year of biology. You take the AP, get out of a semester of intro biology. While some medical schools will look at that and consider it a year of biology, to be safe, you should take at least one additional semester of some upper level biology to make sure that you are covered for the med school's requirement. This formula goes for any of the areas (Biology, Chemistry, Physics, English, and maybe Math) where med schools tend to specify their requirements.
To get a better idea of what the pre-reqs are, check out schools' web sites, or flip through one of those guides to medical schools at the library or book store. Every school is different, so the best strategy this early on is to cover all your bases so that any school that has a problem will be an exception, not the rule.