I went through a similar instance with you while I was at Ohio State. Since a lot of colleges have a time period where you can enroll in classes, depending on how long the semester has been in full swing you may have to tough it out till you enroll for the next semester.
There are some speed bumps that you may run in to:
a) If you are trying to go from a fine arts major to a business major (for example) you may have to apply to the business school prior to taking classes because of institutions in place.
b) Another avenue on a) would be to leave the college that you are already in, moving from the college of pharmacy to the business school or the arts and sciences school which may be hard to do if you decide you want to go back.
Overall it is a pretty easy process once you understand all of the rules and regulations at work and trying to work around those to get what you want.
Hope this helps.
Hi Dakota, switching majors - even during the semester - can be as simple as working with your advisor or using a student portal and changing your major electronically. Most universities even offer exploratory programs or the status of undecided to allow you to take various classes to see what you like/dislike. During college, I switched from majoring in Architecture to an exploratory program 4 weeks into my fall freshman quarter and it was as easy as speaking with my advisor. If you decide to change direction after the deadline to drop classes in a semester, you'll usually have to complete those enrolled classes pending some kind of exemption. Switching can delay when you graduate but depending when in your college career you decide to change your major, the effect can be minimal since a lot of the coursework early on is focused on general classes vs. specific ones tied to a major/minor. My recommendation would be to talk with your advisor and think about why you want to switch in the first place and try to complete some of the general curriculum as you decide what you might want to focus on.
Best of luck and hope this helps!