It is a big decision to pursue MD after completing a PhD. PhD is a degree that takes a lot to finish. First of all, it takes in average of 6-7 years. During that 6-7 years, we go through constant ups and downs, specially a lot of unknowns. It is emotionally and mentally challenging experience that really can deter people from wanting to be in school any longer than necessary.
But there are a few of us who are crazy enough to pursue another professional degree afterwards that would take 7-10 years to complete, which would cost us a ton financially. So anything would help to ease the process. There are two MD programs that are specifically designed for people with PhD. There were not available at the time I applied to med schools. But anyone who is in the same boat now must apply to these programs.
They are a year or a half year shorter, which means it will cost less money and is shorter. And the curriculum is designed for people with PhD, I am not sure how they shortened the program, but I am going to assume that they shortened the basic science portion of the traditional curriculum.
The most important part is that they are designed to train you as physician scientists, so I would assume, you would get training in how to do research as well unlike regular MD programs. Anyways, so Columbia (3yrs) has one and Tulane University (3.5 yrs) has one, and you should check out their websites regarding specific information. I just wanted to you know that you have options.