For Medicine you need Chemistry and often another Science subject (Maths is included as a Science) so really if you do Chemistry and Maths thats your medicine side covered.
You may want to also consider Biology, but i helped my mate search for a Uni for medicine and most offers required Chemistry and another Science, not specifically Biology.
Your doing French.
Now Chemistry and Maths are highly respected subjects, and im sure French would be too. So thats your 3 you'd need for your A-level offer.
So if your good at drama (and enjoy it) then take it, taking 1 subject that isnt as respected isn't going to hinder you.
You may want to take Art if you want to leave your art path open?
So you said 5 subjects:
Chemistry, Maths, French, Drama, Art
or
Chemistry, Maths, French...and 2 of Drama/Art/Biology