DH and I renew our prescriptions in MD when we see the DR. We get the first one filled at the local walmart. We created an online pharmacy account with them. Then, when we need a refill, we go online, log in to our account, and request a refill at whichever Walmart we happen to be close to. We have picked up our meds in Florida and Arizona. Our insurance doesn't seem to have a problem with this, but it is a PPO. You might check if this is a possibility with yours.
2015 Jeep Willys Wrangler
2014 Fleetwood Bounder 33C
States camped: all but Hawaii
more than 1700 days on the road