In the UK, the doctor and pharmacist will ask you if you are on existing medication. I know this because a pharmacist refused to sell me Ibuprofen when I told him that was on Ramapril for high blood pressure.
The point was to be an illustrative example of why it can be useful for health-care providers to share information. HN, predictably, took it as a challenge to try to work around and find as many possible ways to hide the information as they could.