I live in Mexico. I just go to the pharmacy and buy my maintenance meds.
Opiods are difficult, sudafed is illegal, antibiotics and injectables require a prescription, as do other strong pain meds.
So, if you are camped near Mexico, it could be an option for some medications
There are three questions that matter, financially, when it comes to early retirement:
How much do you need?
When do you need it?
How sure are you that it will be there?