there are a fair number of schools that require only 90 credit hours and not the bachelor's degree for you to be able to matriculate. However, the expectation is that you will finish up the remaining credits during your first year (for example, by having med school credits transferred to undergrad). In any case, be careful if you do get in without a BA/BS since many state licensing boards will require you to have an undergrad degree as well
Hope this helps.