Well, I'll answer my own question. Had some extra time, decided to drive down to Mc Allen instead. I was permitted to bring a reasonable amount across the border. I brought back two months' supply of a number of non-scheduled meds. Cipro is NOT permitted. The US Border Patrol/Customs took forever to look over my meds. I think the guy was just trying to fill in time (it was slow at the walk across crossing and there were lots of agents) or couldn't quite firgure out what I had purchased.