As a former Respiratory Therapist for nearly 5 years and now currently in my 2nd year of Medical School, I would not have done it any differently any other way. The experience that I have gained being a RT in the field have helped me tremendously so far in medical school and I hope that it keeps helping me as I go through this path. Why did I choose to go to medical school? It is something that I always wanted, but life has kept me from achieving it until a few years ago.
Initially, I chose RT field for a career in the health care field because I did not know what to do with a BS in Bio and not able to be accepted into medical school after finishing my BS. Needed a profession and wanted to stay in health care and not be a research assistant or teach high school. What this profession has taught me is to how to interact with patients, physicians, nurses and all members of the health care field. It has given me an insight of what physicians goes through during a residency and seeing them become a faculty at the end. Also, you see physicians at their worst and best behavior and how they interact with patients when they are on call and being sleep deprived for over 24 hours. That part is that you don't see when you shadow a physician for a week or a month. The best part of being a RT is too see that you helped the patient feel better and also contribute to their recovery. Also, keep in mind that being a RT you are considered the lowest tier of the Allied Health Profession, but you are the first one to be called if the patient is having breathing problems (in the hospital setting).
Anyhow, to answer your question... if you want to go to medical school, just do what you need to do.. finish the prereqs and score high on the MCAT and shadow a physician to see if this is what you want. Volunteer in a Hospital and get some exposure to the health care and I know that you will do fine. Call the medical schools that you are interested in applying and asked them what are they looking in a candidate. Consider both allopathic and osteopathic medical schools. Do your research and I don't see any problems if you want to go through this path.