Actually, although "Over-the-Counter" refers to drugs that can be bought without any permit or prescription, originally, all of these drugs were still behind a counter, where you asked a pharmacist, and he would simply give it to you "over-the-counter". This way, the pharmacist could advise you on usage, give suggestions, and make sure you don't create a dangerous combination by mixing two drugs incorrectly. However, as pharmacists became more valuble commodites, and we moved into a more self-service world, the Over-The-Counter drugs were moved out onto the shelves, but the name stuck.