If insulin is the med in question, then this is my experience as an insulin taker.
I've been pushing up my distances since I started riding during lockdown - I regularly ride 100 miles when the weather is half decent and did a pair of ~220km rides at the end of the summer (before children back at school/work/weather cut into my available time/motivation.) I was hoping to do one just before Xmas, but being wet for 10h+ put me off!
Working out how to fuel for this duration put me off for a while, but after having ridden them, I realise that as is often the case it's mainly psychological.
My long rides are not organised Audaxes (I must go one some though) but normally loops via friends/family which means I can stop part way and get some proper food (I'm still slightly reluctant to abandon my bike outside a shop, but I will get over this!)
Organised Audax rides might be easier if some controls have food available (and/or stopping somewhere where there are other riders so I don't feel quite so exposed leaving my bike), so this is something I will have to try. While I take food and snack throughout shorter rides (<140km typically), I find that eating something decent half way for a 100 miler or 200km (and aiming for my BG to start rising appreciably before I start riding again) means I don't need to eat so often in the latter half of the ride. I don't tend to need to eat much for the first ~2h (I eat something uncovered before I leave), but by the 5h mark I need to eat quite a bit, so stopping and pushing BG up with proper food is much nicer than needing to eat portable snacky things while riding (at least not needing to eat them quite as often.)
So basically, it won't stop you, even if it does mean paying a bit more attention to fuelling/making sure you have enough supplies with you to make the next control/petrol station/coffee shop/supermarket/etc.
P.S. I realise the distances I'm talking about are short compared to things like LEL 