Your GCSE subjects are completely irrelevant for medicine, other than taking maths, english, and at least double science, and getting at least Cs or above in them. Some courses are actually phasing out subject requirements entirely (Cambridge said they were, not sure what the timeline on that is). Those are of course minimal requirements, and many will exceed those grades in those and other subjects - this is the important thing, getting the best grades possible. The individual subject choices aren't going to make a difference at the GCSE level (they may make a difference at A-level though).