Hi, I am a Student graduating next year and planning to go to study medicine in the UK. The important thing is that you take chemistry HL and math HL/SL. Most universities in the UK require at least 1 science HL and an other science HL or math HL. If you decide to take 2 sciences HL you won't be able to take art. I suggest you take Bio and Chem HL because other universities require bio instead of chem HL, and if you have both you are more likely to get accepted.
Art on the other hand does not really help you to get in medicine so take it only if you have an empty place