Wouldn't the fact that you've done the degree and have more knowledge be an advantage in itself. I mean when it comes to topics related to pharmacology and the like you'll already have an thorough understanding, and won't have to study anywhere near as much as someone with an arts or science degree. Ignore this if it's irrelevant and stupid lol
Yeah, you'll probably get an advantage in the pharmacology sections, and at least some background physiology, microbiology, anatomy. But yeah, there's no credit or exemption granted in the medicine degree. You just have to start from scratch again.