Yes, this is pretty routine here. Go to a doctor's office which accepts walk-ins (most of them do -- in a pinch, every hospital will let you wait briefly for t

Yes, this is pretty routine here. Go to a doctor's office which accepts walk-ins (most of them do -- in a pinch, every hospital will let you wait briefly for the emergency room, or you can Google for "acute care center" or "urgent care center"). They'll ask for your insurance information. Tell them that you have none and will be self-paying. You'll fill out a brief form, be seen by the doctor, likely get a prescription written, and get presented with a bill. It will likely be somewhat larger than what you're used to paying to see the doctor. You can take the prescription to any pharmacy, and pay there for the antibiotics. They will likely be more expensive than you are used to. American doctors, by law and near universal custom, treat patients without regards to citizenship.