Dr. [My Doctor's Name] said to do this...
Dr. [My Other Doctor's Name] said to do that...
Dr. [So-and-so] prescribed this medication... I need to pick it up at...
To Dr. [My Doctor's Name]: Should I take this medication? Or that one?
To Dr. [My Other Doctor's Name]: Do you think that doing this is good for my ailment?
To Dr. [So-and-so]: Dr. [Something] said that I should ask you about this... Should I use this, or that?