Hi There,

Yes you can do this. One of my classmate did this but the swap was between economics and physical education so for her loss was not that much significant. But for you it may become a hefty one as both the subject require you to have the prior knowledge as well to get a good score in your boards. If you now you are not interested to go for medical then instead of swapping the subject you can take it as additional subject not as core and study only to secure decent marks.