If you like the idea of a more cultured and lively living environment, then the central west end is definitely a good place to be, but I wouldn't limit it just to medical students. In the past few years the saint louis metrolink (a light rail system) has become a very useful means of getting around. This rail can get you from the central west end station to WashU's main hilltop campus faster than you would probably get there in a car. The central west end station is in the heart of the Medical school campus. The next stop going west, which is only one stop away from hilltop campus, is forest park/ debaliviere station. There are living options that are much closer to this station than there are ones close to the CWE station. There are even some pretty safe places if you're willing to pay the price for a condo. I'll link to one of the developers. Some of the condo owners rent out to students but you will probably have to find them through craigslist or backpage.
http://www.metropolisdp.com