I can't afford one either, don't get me going.
I call my doctor friends by their names, natch. The doctors I've worked with, or social with -- I have to think about that. My boss was Leonard, or, Goldberg in conversation with others (he is also a writer and his med thrillers are pretty good. I can hear his voice in them. Some of us were semi hemi demi part of it. My copies are just about to go to Goodwill; or maybe not..)
A few of us girlfriends trod a few beach miles to Manhattan Beach. Audrey with a leg in cast; Audrey is a whole 'nother story, re spirit. She was the ballast of our going into that bar, though we all were thirsty. I was introduced to a guy I liked and vice versa. Anyway, he wasn't in our work mainstream, another place. Dear lover, long story. We used first names.
I remember one doctor, funniest man on earth, Mike Derechin, if I'm spelling it right. We called him Derechin. Big on wonderful dog stories, I can still picture him describing his shepherd and the burglar. I fuzzily think he might have first been a lit major. He was a resident passing through but sparked up our lives in the lab. I think he is still in practice, when I looked on the internet.
My regular life doctors, we talk mostly by formal mode in sort of a relaxed way, though not on the first visit. My eye surgeon (the good one) gave me his email, which is informal, so I think of him as Bob.