Here are a couple of oldies: The Citadel by A. J. Cronin and The Country Doctor by Sarah Orne Jewett. I've just read the latter recently. It is interesting to read the assumptions made about a woman having a career before the turn of the last century. The female protagonist makes a conscious decision about her future. I was also surprised that it was simply assumed that a woman could become a doctor. This isn't as good a read as her masterpiece, The Country of the Pointed Firs, but it is interesting.

Have a look at the material found at this link: http://dgmyers.blogspot.com/2009/12/five-books-of-doctors.html

You might find some good titles there. Good luck!

"Doctors" by Erich Segal. It's a fictional novel about a group of students going through Harvard Medical School. I can't recommend it enough. One of my favorite books.

Cutting for Stone by Abraham Verghese

Cancer Ward by Alexander Solzhenitsyn

House of God by Samuel Shem

The Bell Jar by Sylvia Plath

The Andromeda Strain by Michael Crichton (ok, I'm pushing it here)

I know you asked for fiction but there is also really good non-fiction by the likes of Oliver Sacks, Richard Preston and Sylvia Nasar (A Beautiful Mind).