The funny thing is, Warwick have just this year started taking on Geography graduates. OP if you did want to do your geography degree first (seeing as you are good at it) then there is a slim chance you could do grad medicine afterwards, although it is a bit of a gamble.(Original post by marlyly)
That failing, you could do a foundation year and then try to get onto a medicine course, or do a different science degree then apply for medicine as a post-grad (if you're motivated enough to do this).
If i'm completely honest though i think people without anatomy/ pharmacology/biomed/biochem degrees etc will really struggle with graduate medicine. A few of the people who did physics/psychology previously have now dropped out of our year as they couldn't cope with the biological science part.
But we haven't even met!